Session: [B2A-1] S1 : Solar System and Sun-Earth Interactions Date: August 19, 2014 (Tuesday) Time: 11:00~12:20 Room: Room A (Room 101~102) Chair: Jongchul Chae (Seoul National University)
[B2A-1-1] 11:00~11:20
[Invited] Solar Super-Active Regions and Major Activity Events
Jingxiu Wang (National Astronomical Observatories, Chinese Academy of Sciences, China) and Anqin Chen
Each solar activity cycle is characterized by a few super-active regions. They occupied less than 0.5% of total active regions, but produced over 40% of X class X-ray solar flares. Super-active regions resulted in a clear (> 0.1%) depress of total solar irradiance during their central meridian transients. In this sense, they are star- spots seen by remote observers. In this presentation, we first discuss the general statistical properties of super-active regions based on the previous studies of solar cycles 19 to 23; then we focus on the characteristics of vector magnetic fields of super-active regions by using the vector magnetograms obtained at Huairou Solar Observing Station in the last two solar cycles; Finally, we describe in details the super-active regions and major activity events in Solar Cycle 24. So far in Solar Cycle 24, only two active regions meet with the parameterized conditions of super-active regions that established from a detailed statistics for the cycles 21-23. The implications of this unusual fact are discussed.
[B2A-1-2] 11:20~11:35
Development of Daily Solar Flare and CME Probability Models Depending on Sunspot Class and Its Area Change
Kangjin Lee (Kyung Hee University, Korea), Yong-Jae Moon, and Jin-Yi Lee
We investigate the solar flare and CME occurrence probability depending on sunspot class and its area change. For this we use the Solar Region Summary (SRS) from NOAA, NGDC flare catalog, and SOHO/LASCO CME catalog for 16 years (from January 1996 to December 2011). We classify each sunspot class into two sub-groups: ―Large‖ and ―Small‖. For each class, we classify it into three sub-groups according to sunspot area change: ―Decrease‖, ―Steady‖, and ―Increase‖. In terms of sunspot area, the solar flare and CME occurrence probabilities noticeably increase at large and compact sunspot groups (e.g., ‗Fkc‘). In terms of sunspot area change, solar flare and CME probabilities for the ―Increase‖ sub-groups are noticeably higher than those for the other sub-groups. Our results demonstrate statistically that magnetic flux and its emergence enhance solar flare and CME occurrence, especially for compact and large sunspot groups. In case of solar flare, we have developed a daily probability forecast model .Then we apply an evaluation method of NOAA/SWPC to our model. As a result, we find that mean absolute error and mean square error are lower than those of NOAA‘s flare forecast model. We also find that linear association and skill score are better than NOAA‘s values. Our forecast model will be used for space weather operation at KMA.
[B2A-1-3] 11:35~11:50
Lower Temperature Response of an EUV Wave Observed by Hinode/EIS and SDO/AIA
Kyoung-Sun Lee (ISAS/JAXA, Japan), Ryun-Young Kwon, David Brooks, and Toshifumi Shimizu
We investigate an EUV wave observed by Hinode/EIS and SDO/AIA on 2011 August 04. The EUV wave propagates across the solar disk and the wave front passing through a remote active region (AR 11263) is observed by EIS. This EUV wave has already been analyzed using coronal lines, but the lower temperature response to the EUV wave has not been investigated. Using multi-wavelength observations from EIS and
AIA, we determined the intensity and Doppler velocity variation of different temperature lines and compared them. From the comparison, we found an enhancement of the intensity at lower temperatures before the intensity increase seen in the coronal filters of AIA. And a significant enhancement of the red shift (~10 km/s) in the lower temperature line (Si VII, log T ~ 5.8) compared to the increase of the red shift (~3 km/s) in coronal lines (Fe XII, Fe XIII, and Si X, log T ~ 6.1-6.2) when the EUV wave interacts with the active region. We will discuss the impact of the EUV wave on the lower temperature emission.
[B2A-1-4] 11:50~12:05
A Trio of Flares Observed in AR 11087
Anand D. Joshi (Korea Astronomy and Space Science Institute, Korea) and Terry G. Forbes
We investigate three flares that occurred in active region, AR 11087, observed by the Dutch Open Telescope (DOT) on 13 Jul 2010 from 07:30 to 11:55 UT. The AR, located roughly at 27° N, -26° E, has a small U- shaped filament in the southern penumbral region of the sunspot, and a quiescent filament is lying to its west. The first two flares, peaking at 08:35 UT and 10:13 UT, had GOES soft X-ray class B3, whereas the third flare had class C3 and it peaked at 10:51 UT. The third flare was not only the largest in terms of area and brightness, but it also showed a very faint CME associated with it, while the earlier two flares had no associated CME. The DOT observed AR 11087 at seven line positions across the Hα line. Line-of-sight velocity is determined from the DOT observations to observe chromospheric dynamics of the AR and the two filaments. In addition, we use observations from the Solar Dynamics Observatory (SDO) to study the AR. Magnetograms from Helioseismic and Magnetic Imager (HMI) are used to observe the changes in magnetic flux in the AR, while extreme ultraviolet images from the Atmospheric Imaging Assembly (AIA) are used to study dynamics in the AR at higher temperatures. In particular we would be addressing the question as to why only the third flare had a CME associated with it. In this regard, the role played by the quiescent filament would be probed. It will be shown that although there is no visible connection between the AR filament and the quiescent filament, the filament channel still mediates events occurring at the two places.
[B2A-1-5] 12:05~12:20
How Well Can We Estimate the Magnetic Helicity Influx during a Magnetic Flux Emergence with a Footpoint Tracking Method?
G. S. Choe (Kyung Hee University, Korea), and Sunjung Kim
As shown by Démoulin and Berger (2003), the magnetic helicity flux through the solar surface into the solar atmosphere can be exactly calculated if we can trace the motion of footpoints with infinite temporal and spatial resolutions. When there is a magnetic flux transport across the solar surface, the horizontal velocity of footpoints becomes infinite at the polarity inversion line, but the surface integral yielding the helicity flux does not diverge. In practical application, a finite temporal and spatial resolution causes an underestimate of the magnetic helicity flux when a magnetic flux emerges from below the surface. In this paper, we consider emergence of simple two- and half-dimensional magnetic flux ropes and calculate the supremum of the magnitude of the helicity influx that can be estimated from footpoint tracking, per unit length in the invariant direction. The results depend on the ratio of the resolvable length scale and the flux rope diameter. For a Gold-Hoyle flux rope, in which all field lines are uniformly twisted, the observationally estimated helicity influx would be about 90% of the real influx when the ratio is 0.01 and about 45% when the ratio is 0.1. For Lundquist flux ropes, the errors to be incurred by observational estimation would be smaller than the case of the Gold-Hoyle flux rope, but could be as large as 30%. Our calculation suggests that the error in the helicity influx estimate is at least half of the real value or even larger when small scale magnetic structures emerge into the solar atmosphere.
Session: [B2A-2] S7 : Historical Astronomy, Astronomy Education and Public Outreach Date: August 19, 2014 (Tuesday) Time: 11:00~12:35 Room: Room B (Room 103) Chair: Il-Sung Nha
[B2A-2-1] 11:00~11:20
[Invited] Pre-Copernican Non-Ptolemaic Planetary Models: Copernicus and His Islamic Predecessors
Tofigh Heidarzadeh (University of California, USA)
A few decades after the rise of Islam (610 A.D) in Mecca, Muslims were able to establish a vast empire extending from North Africa to India. It was through this expansion that they became familiar with the theory and practice of astronomy from various Persian, Indian, and Hellenistic traditions. During the eighth and ninth centuries, Ptolemy‘s Almagest was translated at least four times into Arabic, and soon Muslim astronomers not only realized that they have to perform new observations to improve the accuracy of basic astronomical parameters, but also they started to find solutions for the most important cosmological problem found in the Ptolemaic astronomy. This problem simply was Ptolemy‘s violation of the Aristotle‘s concept of the uniform circular motion of celestial bodies around the central earth. Ptolemy, by introducing the equant point – the point that was not coincided with the earth but considered as the center of uniform motions – produced a system that was not consistent with the accepted cosmological principle. In this paper, the author will review the major innovative planetary models proposed by Muslim astronomers and will emphasize mainly on those concepts or models which were used by Copernicus in the construction of the heliocentric system of the world. In addition, the possible routs of the transmission of the Islamic non- Ptolemaic planetary models to the Latin West will be discussed.
[B2A-2-2] 11:20~11:35
The Change of the Timekeeping System(時刻制度) Before and After the Solar Calendar in Korea
Goeun Choi (University of Science & Technology, Korea) and Young Sook Ahn
In the Joseon Dynasty, A day divided into 100 gak (刻, approximately a quarter) or 12 Sijin (時辰, double hours) that was composed of half-Sijin as Cho (初, beginnings of double hours) and Jeong (正, mid-points double hours). The timekeeping system was changed from 100 gak to 96 gak with using shíxiàn calendar (時 憲曆) in 1654. And then 12 Sijin was changed to the 24-hours system in the same manner as current with the enforcement of the solar calendar (太陽曆) in 1896. We examine the record of the timekeeping system and notation of hours from the astronomical almanacs and official gazettes during 50 years after 1896. The Korean Empire Government first adopted the standard meridian of the Gyeongseong (former name of the Seoul in Korea) in 1908. However the mean solar time was applied to the almanac since 1913. After 1896, the year of enforcement of the solar calendar, the expression of times on a Korean almanac was written with O-jeon (午前, morning) and O-hu (午後, afternoon). The definition of 1day 24-hours system was first stated by the legislation in 1900. The expression of times was used 24 hours without O-jeon and O-hu in 1916. In daily life, the 24-hours system has used in parallel with 12-hours system divided into morning and afternoon even today.
[B2A-2-3] 11:35~11:50
An Account of Indian Astronomical Heritage from 5th CE to 12th CE
Somenath Chatterjee (Sabitri Debi Institute of Technology, India)
Astronomical observation is the beginning of scientific attitude in the history of mankind. According to Indian tradition, there existed 18 early astronomical texts (siddhāntas) composed by Surya, Pitamaha and many others. Varāhamihira compiled five astronomical texts in a book named pancasiddhāntikā which is now the link between early and later siddhāntas. Indian scholars had no practice to write their own name in their works so, it is very difficult to identify them. Āryabhata is the first name noticed in the book Āryabhatiya. After that most of the astronomers and astro writers wrote their names in their works. In this paper I have tried to analyze the works of the astronomers like Āryabhata, Varāhamihira, Brahmagupta, Bhāskara I, Vateswara, Sripati and Bhāskaracharya; in modern context and get an account of Indian astronomical knowledge. Āryabhata is the first Indian astronomer in stating that the rising and setting of the sun, the moon and other heavenly bodies is due to relative motion of the earth caused by the rotation of the earth about its own axis. He also makes the ‗yuga‘ theory (one Mahayuga = 432000 tears). Varāhamihira compiled pancasiddhāntikā and wrote Bṛhatsamhitā. Brahmagupta is the most distinguished astronomer known to us. His two major works are i) Brahmasphutasiddhānta and ii) Khandkhādaka. Bhāskara I was the follower of Āryabhata. His three known works are Mahābhāskariya, Laghubhāskariya and Āryabhatiyabhāsya. Vateswara follows Āryapaksha and Saurapaksha. His master work is Vateswarasiddhānta. Sripati in his siddhāntasekhara, gives the rule for determining the moon‘s second inequality. Bhāskara II wrote most comprehensive astronomical work in Indian astronomy. The result of this work is an account on India astronomical heritage has been completed. These works are written in Sanskrit language. Very few of these manuscripts are translated in to English but many are yet to be done. So, it is necessary to translate these astronomical texts in to English with proper commentary for the modern scholars. This paper will be helpful in this work.
[B2A-2-4] 11:50~12:05
A Study about Celestial Movement Apparatus of Choi Yu Ji’s Honcheonui
Seon Young Ham (Chungbuk National University, Korea), Sang Hyuk Kim, and Yong Sam Lee
This is a study about celestial movement apparatus of traditional astronomical clock in China and Korea in Joseon Dynasty. We investigated and analyzed the relics and literature records of China and Korea in Joseon Dynasty, and carried out conceptual design of the celestial movement apparatus of Choi Yu Ji(崔攸之, 1603- 1673)‘s Honcheonui(渾天儀, armillary sphere). There were astronomical clocks, traditionally made in East Asia, which had celestial movement apparatuses, reproducing the movements of heavenly bodies mechanically. Through the investigation of relics passed down to the present, Chinese literatures such as 『Jiù Táng Shū(舊唐書)』 「Tiān Wén Zhì(天文誌)」, 『Sòng Shǐ(宋史)』, 『Xin Yi Xiang Fǎ Yào(新儀 象 法要)』 etc, and Korean literatures in Joseon Dynasty such as『Jo Seon Wang Jo Sil Lok(朝鮮王朝實錄)』, 『 Jeung Bo Moon Heon Bi Go(增補文獻備考) 』 , we examined the structures of celestial movement apparatuses of astronomical clock which were made in China and Korea in Joseon Dynasty. The first celestial movement apparatus of Chinese astronomical clock was at the
[B2A-2-5] 12:05~12:20
Imkanur Rukyah as the Best Method in Determining Islamic Caledar
Anuwar Syafiq B. Idrus (Islamic Science University of Malaysia, Malaysia)
Rukyah method is seeing the new moon at sunset on the 29th day of Hijri with the naked eye or with the help of tools such as the telescope and the theodolite. This method is used for the purpose of determining the beginning of Ramadan, Shawwal and Dhu al-Hijjah in the country before the adoption of rukyah and mathematics. According to the calculation method enacted, the new month starts when the conjunction occurs before sunset regardless of whether or not there is new moon. Hijri calendar that uses this concept called the Ultimate Hijri Calendar. If the existence of the new moon after the conjunction serve as the basis of determining the initial months, the calendar is called Hijri Calendar Wujudul - hilal.
[B2A-2-6] 12:20~12:35
Study on the Manufacturing Technology and Astronomical Analysis of Portable Sundials of the Late Joseon
Sang Hyuk Kim (Korea Astronomy and Space Science Institute, Korea), Ki-Won Lee, and Yong Sam Lee
It is known that many clocks were manufactured by Jinju Kang family in the late Joseon dynasty. In particular, Kang Yun (姜潤, 1830~1898) and his younger brother, Kang Geon (姜健, 1843~1909), made twelve portable sundials: nine of scaphe sundials and three of planar ones. In this study, we investigate the physical characteristics of those sundials and verify the accuracy of the lines related with the time for three sundials. First, we compiled the catalogue of twelve sundials with the ownership, material, dimension, production year, and so forth based on various references. Then, we examined the lines of the hour and 24 seasonal subdivisions including the position of Yeongchim (gnomon) for selected sundials. The basic methodology is to obtain the 2D image of a real sundial using a camera or scanner and compare with the result of theoretical calculations. As a result, we found that the sundials are moderately precise considering the fact that they are portable. In conclusion, we believe that the projection method employed in this study is useful to verify the accuracy of a sundial, in particular of the old one needed to minimize physical damage.
Session: [B2A-3] S3 : Stars, Exoplanets and Stellar Systems Date: August 19, 2014 (Tuesday) Time: 11:00~12:25 Room: Room C (Room 104) Chair: Irina Voloshina (Sternberg Astronomical Institute)
[B2A-3-1] 11:00~11:20
[Invited] Magnetic CV as a Bright Representative of Close Binaries
Shengbang Qian (Chinese Academy of Sciences, China), Liying Zhu, Liang Liu, and Wenping Liao
Mass transfer is very important to understand the evolution and observational properties of close binary stars (CBs). Due to the lack of an accretion disk, eclipsing profiles of polars are the best source to study the character of mass transfer in CBs. In the past five years, we have monitored about 10 eclipsing polars (e.g., DP Leo and HU Aqr) by using several 2-m class telescopes and about 100 eclipse profiles were obtained. In this talk, I will review some progresses of our research group at YNOs. The first direct evidence of variable mass transfer in a CV is obtained and we show that it is the dark-spot activity caused the mass transfer in CVs. Magnetic activity cycles of the cool secondary were detected and we show that the variable mass transfer is not caused by magnetic activity cycles. These results will shed light on the structure and evolution close binary stars (e.g., CVs and Algols).
[B2A-3-2] 11:20~11:40
[Invited] Accretion Processes in Cataclysmic Variables with Magnetic Field
D. V. Bisikalo (Institute of Astronomy RAS, Russia)
We present a review of physical processes occurring due the mass transfer between the components of magnetic cataclysmic variables (mCV). Special attention is paid to the description of the magnetic field influence on accretion processes. In the frame of a self-consistent description of MHD flows in mCV we have derived the conditions of disk formation and found a criterion that splits two types of the flow, corresponding to intermediate polars and polars. We have also investigated variations of the main characteristics of the disks depending on the value of the magnetic induction and analyzed the process of magnetic field generation in the disks. In particular, it has been found that the quasi-periodic generation of the toroidal magnetic field in the disks leads to the alternation of accretion and decretion regimes in the inner regions of the disk. The main observational manifestations of the numerically found flow structure elements are also described.
[B2A-3-3] 11:40~11:55
Period Variations of Superhumps in SU UMa Stars
Akira Imada (National Astronomical Observatory of Japan, Japan) and Taichi Kato
We review recent results on superhump period variations in SU UMa-type dwarf novae. Our statistical studies have revealed that the evolution of the superhump period (Psh) is basically composed of three stages: stage- A during which the Psh is long and constant, stage-B during which Psh increases as the superoutburst proceeds, and stage-C during which Psh is short and constant. We also introduce a new method of estimating mass ratio using stage-A Psh. This method can extend to e.g., low mass X-ray binaries or AM CVn stars if stage-A Psh is well determined. Finally we briefly introduce our telescopes, instruments, and research members. This may motivate you to collaborate with our group.
[B2A-3-4] 11:55~12:10
Dynamical Effects From Mass Transfer in Non-Magnetic CVs
Michele M. Montgomery (UCF Physics, USA)
Mass transfer is ubiquitous in close binary systems. With higher potential energies transferring into higher kinetic energies, effects by mass transfer may include dynamics that may in turn modulate the light from the system. With the disk producing most of the light in non-magnetic Cataclysmic Variable (CV) systems, mass transfer effects may include disk tilt, warp, holes, plumes, etc. In this work, we review our latest 3D HD numerical simulation results and compare these results with those obtained from observations.
[B2A-3-5] 12:10~12:25
BVR photometric Analysis of Intermediate Polar MU Cam
Jiwon Park (Chungbuk National University, Korea), Joh-na Yoon, Yonggi Kim, and Ivan L. Andronov
Results of 46 night of CCD BVR photometry of the Intermediate Polar MU Cam obstained at 1m Telescope of LOAO and 60cm Telescope of CBNUO between 2005 and 2014 are presented. Using multi-periodic approximation and running approximation, times of extrema and the new ephemeris for the orbital and spin period: BJD(spin)=2454085.50725(91)+0.013740942(13)∙E-1.15(10)X10-12∙E2 and BJD(orb)= 2454085.46(19)+ 0.1966410(26 ) ∙E Increasing the spin period is also confirmed through the O-C method as P=-2.20(14)∙ 10-12s/s. The periodogram analysis for 3 regions in V filter data and 4 regions in R filter data shows the existence of the beat frequency in the data of 2005-2006. This season corresponds to the low state and there are no beat frequency found in the high state, but the used data have no clear magnitude difference between the low state and high state. It is highly needed to get more accurate data in the further monitoring to make clear for the existence of the beat frequency. Period analysis for the new variables, V440 Cam and V442 Cam, found in the region of MU Cam provides the new orbital periods, P=1.d151439 and P=0.d4426442 respectively. Determining the physical parameters of these variables is also possible through an accurate photometry for these variables in the future.
Session: [B2A-4] S4 : Galaxies, AGN and Cosmology Date: August 19, 2014 (Tuesday) Time: 11:00~12:25 Room: Room D (Room 105~106) Chair: Sascha Trippe (Seoul National University)
[B2A-4-1] 11:00~11:20
[Invited] Evidence for the Luminosity Evolution of Type Ia Supernovae from Early-type Host Galaxies
Young-Wook Lee (Yonsei University, Korea), Yijung Kang, Young-Lo Kim, Dongwook Lim, and Chul Chung
Supernovae type Ia (SNe Ia) cosmology is providing the only direct evidence for the presence of dark energy. This result is based on the assumption that the look-back time evolution of SNe Ia luminosity, after light-curve shape correction, would be negligible. However, the most recent compilation of SNe Ia data shows systematic difference in the Hubble residual (HR) between the E and Sd/Irr galaxies, indicating that the light-curve fitters used by the SNe Ia community cannot quite correct for a large portion of the population age effect. In order to investigate this possibility more directly, we have obtained low-resolution spectra for 30 nearby early-type host galaxies. This data set is used to estimate the luminosity-weighted mean ages and metallicities of host galaxies by employing the population synthesis models. We found an interesting trend between the host galaxy age and HR, in the sense that younger galaxies have positive residuals (i.e., light-curve corrected SNe Ia luminosity is fainter). This result is rather independent of the choice of the population synthesis models employed. Taken at face value, this age (evolution) effect can mimic a large fraction of the HR used in the discovery of the dark energy, but further observations and analyses are required to confirm the trend reported here.
[B2A-4-2] 11:20~11:40
[Invited] Sustaining Galaxy Evolution: the Role of Stellar Feedback
Atefeh Javadi (Institute for research in Fundamental Sciences, Iran), Jacco Th. Van Loon, and Habib Khosroshahi
We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group galaxy M33. The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. The pulsating giant stars (AGB and red supergiants) are identified and their distributions are used to derive the star formation rate as a function of age. These stars are also important dust factories; we measure their dust production rates from a combination of our data with Spitzer Space Telescope mid-IR photometry. The mass-loss rates are seen to increase with increasing strength of pulsation and with increasing bolometric luminosity. Low-mass stars lose most of their mass through stellar winds, but even super-AGB stars and red superginats lose ~40% of their mass via a dusty stellar wind. We construct 2-D map of the mass-return rate, showing radial decline but also local enhancements due to agglomerations of massive stars. By comparing the current star formation rate with total mass input to ISM, we conclude that the star formation in the central regions of M33 can only be sustained if gas is accreted from further out in the disc or from circum-galactic regions. Now we are extending our study to the other galaxies in Local Group including Small and Large Magellanic Clouds. Ultimately we will study the feedback of evolved stars in Virgo cluster of galaxies with ELT observations.
[B2A-4-3] 11:40~11:55
Molecular Gas Properties under ICM Pressure in the Cluster Environment
Bumhyun Lee (Yonsei University, Korea) and Aeree Chung
We present CO properties of four spiral galaxies (NGC4330, NGC4402, NGC4522, NGC4569) in the Virgo cluster that are undergoing different ram pressure stages due to the intra cluster medium (ICM). The goal is to probe the detailed properties of the molecular gas under strong ICM pressure. In this work, using high- resolution millimeter data taken with the Submillimeter Array (SMA), we investigate the CO morphology and kinematics of the sample. Also, combining with the Institut de RadioAstronomie Millimetrique (IRAM) data, we study spatially resolved temperature and density distributions of the molecular gas. Compared with multi- wavelength data (optical, HI, UV, Hα), we discuss how molecular gas properties and star formation activity change while a galaxy experiences HI stripping. This study suggests that ICM pressure can well modify the physical and chemical properties of the molecular gas even if stripping does not take place in the molecular gas. We discuss how this affects the star formation rate and galaxy evolution in the cluster environment.
[B2A-4-4] 11:55~12:10
Tracing Recent Star Formation of Red Early-type Galaxies
Jongwan Ko (Korea Astronomy and Space Science Institute, Korea), Ho Seong Hwang, Myungshin Im, and Jong Chul Lee
We study the mid-infrared (IR) and near-ultraviolet (UV) excess emissions of early-type galaxies (ETGs) on the optical red-sequence at z < 1 using a spectroscopic sample of galaxies in the Sloan Digital Sky Survey (SDSS) Data Release 7 and in the fields of Great Observatories Origins Deep Survey (GOODS). In the mass- limited GOODS sample of 1025 galaxies with Mstar > 1010.5M⊙ and 0.4 < z < 1.05, we identify 696 Spitzer 24 μm detected (above the 5σ) galaxies and find them to have a wide range of NUV-r and r-[12 μm] colors despite their red optical u−r colors. Even in the sample of very massive ETGs on the red sequence with Mstar > 1011.2M⊙, more than 18% show excess emission over the photospheric emission in the mid-IR. The combination with the results of SDSS red ETGs in the local universe suggests that the recent star formation is not rare among quiescent, red ETGs at least out to z ~1 if the mid-IR excess emission results from intermediate-age stars or/and from low-level ongoing star formation. Our color−color diagram including near- UV and mid-IR emissions are efficient not only for identifying ETGs with recent star formation, but also for distinguishing quiescent galaxies from dusty star-forming galaxies.
[B2A-4-5] 12:10~12:25
The Galactic-Scale Molecular Outflows in Starburst Galaxies NGC 2146 and NGC 3628
An-Li Tsai (National Centraul University, Taiwan) and Satoki Matsushita
In order to understand how the galaxies mass loss affects the galaxies evolution, I study how nearby galaxies loss their fuel, molecular gas, through galaxy activities. Starburst galaxies are good candidates to study the molecular gas consumption in galaxies. They are currently undergoing intense star formation in the central region of the galaxies, and their strong star formation produced galactic-scale outflow and ejected large amount of molecular gas. However, the accurate measurement of losing molecular gas are very rare because it is difficult to directly observe molecular outflows or due to their diffuse/extended nature and the poor instrumental sensitivities. So far there are only a few studies on galactic-scale molecular outflows due to the sensitivity limitation of telescopes. Our studies provides two samples of starburst galaxies, NGC 2146 and NGC 3628. We used Nobeyama Millimieter Array (NMA) data and Chandra soft X-ray data to study the molecular outflows and their interaction with ionized outflows. We found that the molecular gas are pushed by the hot ionized outflows due to their high pressure. Beside, the molecular outflows have larger mass loss rate than the star forming rate. This indicates that the molecular outflows dominate the gas consumption in starburst galaxies. Since the fraction of starburst galaxies is higher in distant universe than in the local universe, this study can bridge the gap between our knowledge between local and distant galaxies, and could help us to understand the galaxy evolution in the universe.
Session: [B2A-5] S5 : Compact Objects, High Energy and Particle Astrophysics Date: August 19, 2014 (Tuesday) Time: 11:00~12:25 Room: Room E (Room 107) Chair: Ronald Taam (Academia Sinica Institute of Astronomy and Astrophysics)
[B2A-5-1] 11:00~11:20
[Invited] Outflow from Hot Accretion Flows
Feng Yuan (Shanghai Astronomical Observatory, China), Defu Bu, and Maochun Wu
Both HD and MHD numerical simulations of hot accretion flows have indicated that the inflow accretion rate decreases inward. Two models have been proposed to explain this result. In the adiabatic inflow–outflow solution (ADIOS), this is because of the loss of gas in the outflow. In the alternative convection-dominated accretion flow model, it is thought that the flow is convectively unstable and gas is locked in convective eddies. We investigate the nature of the inward decrease of the accretion rate using HD and MHD simulations. We calculate various properties of the inflow and outflow such as temperature and rotational velocity. Systematic and significant differences are found. These results suggest that the inflow and outflow are not simply convective turbulence; instead, systematic inward and outward motion (i.e., real outflow) must exist. We have also analyzed the convective stability of MHD accretion flows and found that they are stable. These results favor the ADIOS scenario. We suggest that the mechanisms of producing outflow in HD and MHD flows are the buoyancy associated with the convection and the centrifugal force associated with the angular momentum transport mediated by the magnetic field, respectively. The latter is similar to the Blandford & Payne mechanism but no large-scale open magnetic field is required. We discuss one observational application, namely the formation of the Fermi bubbles in the Galactic center.
[B2A-5-2] 11:20~11:40
[Invited] Gravitational Radiation Captures of Two Black Holes
Gungwon Kang (Korea Institute of Science and Technology Information, Korea), Jakob Hansen, Peter Diener, Hee-Il Kim, and Frank Loeffler
We have investigated gravitational radiation capturing processes of two non-spinning equal mass black holes in weakly hyperbolic orbits (e.g., eccentricities of 1.0 ~ 1.4) by solving Einstein equations numerically. In the presence of a supermassive black hole in galactic nuclei, fully general relativistic understandings of such dynamical capturing processes become important to the formation of black hole binaries. We find that most of gravitational wave emissions occur when two black holes encounter closely. This explains why the multipole contributions higher than l=2 are negligible (e.g., about 1%) even if the orbit is quite eccentric or non-quasi- circular. The capturing cross section has been compared with the corresponding 2.5 post Newtonian results. They agree well for small initial energies, but differ up to about 40% for large initial energies. We also analyzed the features of energy and angular momentum radiations and gravitational wave forms.
[B2A-5-3] 11:40~11:55
Constraining the Magnetic Field in the Accretion Flow of Low-Luminosity Active Galactic Nuclei
Erlin Qiao (Chinese Academy of Sciences, China) and B. F. Liu
Observations show that the accretion flows in low-luminosity active galactic nuclei (LLAGNs) probably have a two-component structure with an inner hot, optically thin, advection dominated accretion flow (ADAF) and an outer truncated cool, optically thick accretion disk. It is found that the truncation radius as a function of mass accretion rate is strongly affected by including the magnetic field within the framework of disk evaporation
model, i.e., an increase of the magnetic field results in a smaller truncation radius of the accretion disk. In this work, we calculate the emergent spectrum of an inner ADAF + an outer truncated accretion disk around a super-massive black hole. It is found that an increase of the magnetic field from β=0.8 to β=0.5 (with magnetic pressure Pm =B2/8ￗ = (1-β) Ptot, Ptot= Pgas+ Pm ) results in an increase of ~8.7 times of the luminosity from the truncated accretion disk, meanwhile results in the peak emission of the truncated accretion disk shifting towards a higher frequency by a factor of ~5 times. We found that the equipartition of gas pressure to magnetic pressure, i.e., β=0.5, failed to explain the observed anti-correlation between L2-10 keV /LEdd and the bolometric correction κ2-10keV (with κ2-10 keV = Lbol /L2-10 keV). The emergent spectra for larger value β=0.8 or β=0.95 can well explain the observed L2-10 keV/LEdd - κ2-10keV correlation. We argue that in the disk evaporation model, the electrons in the corona are assumed to be heated only by a transfer of energy from the ions to electrons via Coulomb collisions, which is reasonable for the accretion with a lower mass accretion rate. Coulomb heating is the dominated heating mechanism for the electrons only if the magnetic field is strongly sub-equipartition, which is roughly consistent with observations.
[B2A-5-4] 11:55~12:10
Mass Accretion Rate of Transonic Rotating Accretion Flow
Du Hwan Han (Kyungpook National University, Korea) and Myeong-Gu Park
We studied how the mass accretion rate of transonic rotating accretion flow depends on the physical conditions of gas at the outer boundary, equation of state of gas, and the viscosity description. The flow with angular momentum much smaller than the Keplerian value has mass accretion rate similar to the classic Bondi accretion rate. However, the flow with significant angular momentum has mass accretion rate much smaller than the Bondi rate. We calculated the mass accretion rate under various equation of state and viscosity description. The implication of the result regarding the growth of supermassive black holes is discussed.
[B2A-5-5] 12:10~12:25
Accretion-Jet Model for the Hard X-ray Γ-L Correlation in Black Hole Accreting Systems
Qi-Xiang Yang (Shanghai Astronomical Observatory, China), Feng Yuan, and Fu-Guo Xie
We investigate the correlation between the 2-10 keV X-ray luminosity (in unit of Eddington luminosity; ) and the photon index of the X-ray spectrum for both active galactic nuclei (AGNs) and black hole X-ray binaries (BHXBs). We make use of the observational data from a large sample and the sources span a wider range of luminosity than all previous works. We find that the photon index is positively or negatively correlated with the X-ray luminosity , for above or below a critical value,. This result is the same for BHBs and AGNs and consistent with previous works. But the correlation slopes are different for different individual sources. Moreover, when, we found, which is more evident in the BHB subsample, that the photon index is roughly independent of the X-ray luminosity. We explain these correlations in the framework of a coupled hot accretion flow-jet model. The hot accretion flow includes the advection-dominated accretion flow (ADAF) and the luminous hot accretion flow (LHAF) when the accretion rates are low and high, respectively. The latter will become into two-phase due to the thermal instability when the accretion rate is higher and may finally evolve into the usual ''disk-corona'' configuration. The positive correlation is explained as because of the Compton scattering of the seed photons from cold clumps in the two-phase accretion flow, the negative correlation at moderate X-ray luminosity regime is because of the change of optical depth of hot accretion flow. The slope of the negative correlation is a function of the parameter of the hot accretion flow, which describes the fraction of the turbulent dissipation that directly heats electrons. This may be the reason why the correlation slope of different sources are different. At last, the constant at very faint X-ray luminosity regime is because that the X- ray radiation is dominated by the jet rather than the accretion flow.
Session: [B2A-6] S6 : Observing Facilities and International Collaborations Date: August 19, 2014 (Tuesday) Time: 11:00~12:30 Room: Room F (Room 108) Chair: Ajit Kembhavi (Inter-University Centre for Astronomy and Astrophysics)
[B2A-6-1] 11:00~11:20
[Invited] Giant Magellan Telescope: Korean Prospects
Byeong-Gon Park (Korea Astronomy and Space Science Institute, Korea)
Giant Magellan Telescope (GMT) project is one of the three next generation extremely large telescope (ELT) development projects, which is being conducted by a consortium of multiple international institutions. The diameter of the GMT is 25m where seven 8.4m circular segments form a single elliptically shaped surface. Secondary mirror of the GMT is also formed with seven 1.06m circular mirrors where each segment is aligned with matching primary segment to form a Gregorian focus. GMT will be installed at the Las Campanas Peak in Chilean Andes at an altitude of 2,550m. In 2014, GMT project passed important milestones in its project plan that includes system level preliminary design review, cost and structural review, and entered into a construction / commissioning phase. Korea joined GMT project in 2009 and Korea Astronomy and Space Science Institute (KASI) has been acting as a Founder of the GMT project representing whole Korean astronomical community. By joining GMT project, Korean astronomical community anticipates a great leap to lead the most contemporary scientific research topics in the era of ELTs. In preparation for the brilliant future, KASI strives to promote research capability of Korean community by gaining access to large telescopes of 4m to 8m in diameter, holding annual schools for students, running international fellowship programs with partner institutions of the GMT project. In addition, KASI is developing the first generation instruments of the GMT in collaboration with other partners and trying to lead the fabrication of the secondary mirrors of the telescope. Also, KASI encourages Korean industries to participate in the manufacturing of mechanical parts of the telescope such as mount, motor drives, and enclosure, and building observatory facilities where we believe there are world-leading companies in these areas in Korea.To be announced
[B2A-6-2] 11:20~11:35
[Invited] The TMT Project and The Japanese Perspective
Masanori Iye (TMT International Corporation, Japan)
*To be announced
[B2A-6-3] 11:35~11:45
[Invited] TMT: The Indian Perspective
G. C. Anupama (Indian Institute of Astrophysics, India)
As one of the partners of the TMT project, India is looking to supply a good fraction of the primary segments hardware, as well as contribute to the telescope control software. Fabrication of prototypes of some of these components are being undertaken by industries in India. A brief description of the various TMT related activities underway in India will be provided in the talk.
[B2A-6-4] 11:45~12:00
[Invited] The Square Kilometre Array - One of the Great Observatories of the Next Decade
Michael Kramer (Max-Planck-Institut fuer Radioastronomie, Germany)
The Square Kilometre Array (SKA) will be constructed at the end of this decade. Upon completion, it will be the largest radio telescope in the world, covering the radio frequency part of the electromagnetic spectrum as one of the Great Observatories for the decades to come. Its construction will be done in phases, allowing science operation already while the telescope is still being completed. Apart from addressing five internationally selected Key Science Projects, the SKA will also be known for overcoming a number of technology challenges. This talk will summarize the status of the SKA Project, its science and the technology solutions that will be employed.
[B2A-6-5] 12:00~12:15
The Australian SKA Pathfinder Telescope
Lisa Harvey-Smith (CSIRO Astronomy & Space Science, Australia)
The Australian Square Kilometre Array Pathfinder (ASKAP) is a cutting-edge radio interferometer comprising 36 x 12 metre antennaslocated at the Murchison Radio-astronomy Observatory in Western Australia. In the first five years of operation, approximately 75% of ASKAP‘s time will be spent conducting large-area sky surveys in the frequency range 700 to 1800 MHz. Ten science survey teams have been assembled, comprising over 600 astronomers around the world. As part of the international SKA project, ASKAP will later form the core of the of the Phase 1 SKA Survey telescope in Australia. ASKAP features a new type of radio astronomy receiver called a phased array feed, which gives the telescope its extraordinarily fast survey capability through its extremely wide field-of-view. Six antennas have already been fitted with prototype phased array receivers and are currently being used as a powerful commissioning instrument called the Boolardy Engineering Test Array (BETA). A suite of 30 second- generation phased array feeds are under construction and will be fitted to ASKAP antennas in 2015. The science goals of ASKAP include: • Galaxy formation and gas evolution in the nearby Universe through extragalactic HI surveys • Evolution, formation and population of galaxies across cosmic time via high resolution, confusion limited, continuum surveys • Characterisation of the radio transient sky through detection and monitoring (including VLBI) of transient and variable sources, and • Evolution of magnetic fields in galaxies over cosmic time through polarization surveys. The construction of ASKAP is almost complete. The observatory is fully established in a region that has a legal framework under both Federal and State legislation that protects the radio-quiet environment. All roads, on-site buildings, fibre-optic networks and supercomputing facilities are completed. The 36 dishes are installed. Telescope control software and data pipelines have been released. The data archive is in an advanced stage of development. This talk will describe ASKAP's capabilities and scientific goals, report on the latest commissioning results, discuss the challenges faced and lay out plans for the commencement of early science operations in 2015.
[B2A-6-6] 12:15~12:30
[Invited] The LIGO-India Project
Tarun Souradeep (IUCAA, India)
Direct detection of gravitational wave (GW) signal from astrophysical events, such as,mergers of compact objects, is widely believed to be imminent in this decade given the advent of advanced Laser interferometric Gravitational wave observatories (LIGO). For the astronomy community, it promises an entirely new window into the universe to add to multi-messenger astronomy. However, for meaningful electromagnetic follow up, it will be important to be locate the GW sources on the sky. I will present LIGO-India, a proposal for a GW observatory on Indian soil that would be provide this critical element to the launch of GW astronomy orldwide. The proposal has been recommended as one of the mega-science projects by the Planning Commission of India and currently awaits a final approval from the Indian government.
Session: [B2B-1] S1 : Solar System and Sun-Earth Interactions Date: August 19, 2014 (Tuesday) Time: 14:00~15:30 Room: Room A (Room 101~102) Chair: Jingxiu Wang (National Astronomical Observatories)
[B2B-1-1] 14:00~14:15
Digitized Archive of Kodaikanal Ca-K Spectroheliograms and Solar Activity Cycle
V. Muthu Priyal (Indian Institute of Astrophysics, India), Jagdev Singh, D. Banerjee, and B. Ravindra
The spectroheliograms in Ca-II K line obtained at Kodaikanal since 1907 have been digitized using 4k x 4k CCD camera. After CCD and intensity calibration we identified different chromospheric features. Using different thresholds of the intensity contrast and size criterion different features are classified as the plage (> 1.35 and area > 1-arc-min2) , enhanced-network (>1.35, area < 1-arcmin2) , active-network (1.25 -1.35), and quiet-Sun (1.15-1.25). For 100 years Ca-K spectroheliograms (1907 – 2007), the variation of Plage index, enhanced-work, active-network and quiet network index are studied with the solar cycle phase. The centroid of each individual plages corresponding to different latitudes are also identified using auto detection methods as developed using IDL, and the chromospheric differential rotation rates are calculated. Furthermore, we study the variation of the contribution of CaII K plage flux to the total solar irradiance. In this presentation we will present the Kodaikanal data archive and some important and interesting result obtained from our KKL Ca- K Spectroheliograms as outlined above.
[B2B-1-2] 14:15~14:30
Spectral Inversion of the Hα line for a Plasma Feature in the Chromosphere of the Quiet Sun
Jongchul Chae (Seoul National University, Korea)
We propose a generalization of Becker's cloud model (BCM): an embedded cloud model (ECM)—for the inversion of the core of the Hα line spectrum of a plasma feature either lying high above the forest of chromospheric features or partly embedded in the outermost part of this forest. The fundamental assumption of the ECM is that the background light incident on the bottom of the feature from below is equal to the ensemble-average light at the same height. This light is related to the observed ensemble-average light via the radiative transfer that is described by the four parameters newly introduced in addition to the original four parameters of the BCM. Three of these new parameters are independently determined from the observed rms contrast profile of the ensemble. We use the constrained χ2 fitting technique to determine the five free parameters. We find that the ECM leads to the fairly good fitting of the observed line profiles and the reasonable inference of physical parameters in quiet regions where the BCM cannot. Our first application of this model to a quiet region of the Sun indicates that the model can produce the complete velocity map and Doppler width map of the region.
[B2B-1-3] 14:30~14:45
Loss of Relativistic Electrons at Geosynchronous Orbit During Quiet Geomagnetic Intervals: the Role of EMIC Waves
K. Hyun (Kyung Hee University, Korea), K.-H Kim, E. Lee, and D.-H. Lee
The dynamics of relativistic electrons (REE) in Earth‘s radiation belt is of much current interest in space weather because many spacecraft failures and anomalies have been attributed to REE. The flux of REE in Earth‘s radiation belt is highly dynamic. Typically, dramatic changes of flux occur during a geomagnetic storm period. At that time, loss and enhancement of flux occur sequentially. It was known that the loss process is dominant in a main phase of storm and various mechanisms associated with the loss of REE can occur.
Those are magnetopause shadowing effect, magnetic moment scattering and wave-particle interaction considering a permanent loss. However, it is difficult to identify what is the dominant loss process during the interval. In this study, we have examined REE losses at geosynchronous orbit during quiet geomagnetic intervals in 2008. During the intervals, rapid or sudden decrease of REE flux was observed by GEO satellites (GOES 10, 11 and 12) and well defined electromagnetic ion cyclotron (EMIC) waves were detected. It was known that the rapid loss of REE are closely associated with the EMIC-REE interaction. We have identified that the rapid losses of REE were caused by EMIC-REE interaction. To do that, we have checked the conditions for EMIC-REE interaction and loss time scales based on quasi-linear theory. We have used the cold plasma density from THEMIS satellites and magnetic field data from GOES satellites. Additionally, we have identified that other loss processes were not dominant or less effective compared with the energetic proton flux. We have found out that the most of rapid losses of REE during quiet geomagnetic intervals occurred when the plasmapause expanded beyond the geosynchronous altitude (6.6 Re) and cold plasma density was high enough to cause the EMIC-REE interaction.
[B2B-1-4] 14:45~15:00
Research of Radiation Belt Models in KASI
Jaejin Lee (Korea Astronomy and Space Science Institute, Korea), Kyung-Chan Kim, and Jong-Gil Lee
In Korea, the role of GEO satellites has been increased significantly in the area of communication, military, meteorology and monitoring of marine environment. In order to protect these national space assets from severe space environment, understanding magnetospheric phenomena and predicting space weather condition have been demanded continuously. In response to these requests, Korea astronomy and Space science Institute(KASI) constructed an antenna system receiving space weather data from a NASA mission, Van Allen Probes in 2012. The real time measurements of plasmas and fields provide useful information for predicting space storms that could potentially affect GEO satellite operation. In addition, for predicting space environment on the geosynchronous orbit, practical space weather model should be developed. KASI develop assimilation code based on the real time observational data to predict variation of energetic particles on the GEO orbit.
[B2B-1-5] 15:00~15:15
The Signatures of Worldwide Solar Quiet of the Horizontal Field Intensity on Annual Time Scale
Owolabi T. P. (Obafemi Awolowo University, Nigeria), Rabiu A. B., Bolaji O. S., and Olayanju G. M.
The morphologies of solar quiet field of the horizontal magnetic field intensity Sq(H) across the globe were investigated with Sixty-four (64) geomagnetic stations at different latitudinal and longitudinal sectors on an annual time scale. This investigation on 64 observatories was made possible with data from January to December, 1996 a year of low solar activity. Geomagnetic stations around the north and south of the high latitudes were observed to have highest magnitudes of Sq(H) in the range of 130-260 nT compared to the ranges at the middle (78-100 nT) and low (78-140 nT) latitude. Interestingly, the highest magnitude of about 260 nT was observed at the south of high latitude (HL) and the minimum value of 130 nT was observed at the north of the HL. Our results further showed that these highest magnitudes of Sq(H) at HL were more pronounced at the eastern axes compared to western axes of the longitude. At the low latitude, highest 0 0 magnitude of Sq(H) with no shift was observed at 0 N/S across the longitude, with a slight shift to around 8 N at 18.750E and with a greater shift to around 150N at 141.280E. This continuous shift of abnormal increment in the magnitude of Sq(H) at the low latitude shows that the jet focus as well continuously changes its position to the north of higher latitude as one moves towards the eastern axis of the longitude. Physical mechanisms responsible for these phenomena were investigated.
[B2B-1-6] 15:15~15:30
Deep Solar Minimum During SC-23, SC-24 and its Energetic Storms
Ahmed A. Hady (Cairo University, Egypt)
The paper examines the deep minimum of solar cycle 23, and solar cycle 24. Potential impact of energetic storms on geomagnetic field and space weather were studied. In addition, a source region of the solar winds at solar activity minimum, especially in the solar cycle 23. Solar activities have had notable effect on space weather changes. There is a close association between solar proton events and solar radio bursts occurring at several frequencies, 1-2 days before. The 245 MHz radio bursts associated with proton events have
intense peak fluxes (up to 650000 sfu). The resulting correlations may be used for providing short-term prediction of solar proton events.
Session: [B2B-2] S7 : Historical Astronomy, Astronomy Education and Public Outreach Date: August 19, 2014 (Tuesday) Time: 14:00~15:30 Room: Room B (Room 103) Chair: Young Woon Kang (Sejong University)
[B2B-2-1] 14:00~14:20
[Invited] The Zero-point of the Zodiac of the Hindu Astronomers in Ancient India
Amalendu Bandyopadhyay (M. P. Birla Institute of Fundamental Research, M. P. Birla Planetarium, India)
In modern astronomy the vernal equinoctial (VE) point is taken as the starting point for measuring celestial longitudes. Due to the precession of equinoxes, the above point is receding back along the ecliptic. As a result, the longitudes of fixed stars are increasing every year. In ancient India, the Hindu astronomers did not favour the idea of fixed stars changing their longitudes. In order to stabilize the zodiac, they had taken as the origin a point which is fixed on the ecliptic and as such is quite different from the VE point. This initial point being a fixed one, the longitude of stars measured from this origin remain invariable for all time. The distance between this fixed initial point and the VE point is called ayanamsa in Hindu astronomy and the zodiac starting from this fixed origin, is known as fixed zodiac. The longitude of a heavenly body measured from this fixed point is known as sidereal longitude in Hindu astronomy. There was an epoch in the past when this initial point coincided with the VE point and the sidereal zodiac coincided with the tropical one. At that time, the value of ayanamsa was zero and thus the epoch may be called the zero-year. There is controversy over the determination of the zero-year. The reasons for the choice for the fixed zodiacal system by the Hindu astronomers as well as the epoch of zero-year have been found out on the basis of inferences available in various astronomical treatises of ancient India in Sanskrit.
[B2B-2-2] 14:20~14:40
[Invited] Jesuit Astronomer Royal in China and 3,083 Stars in the Star-Catalogue Yixiangkaocheng
Sang-Hyeon Ahn (Korea Astronomy and Space Science Institute, Korea)
The stars in the Chinese star catalogue, Yixiangkaocheng, which were edited by the Jesuit astronomer Kögler in AD 1744 and published in AD 1756, are identified with their counterparts in the Hipparcos catalogue. The equinox of the catalogue is confirmed to be J1744.0. By considering the precession of equinox, proper motions and nutation, the star closest to the location of each star in Yixiangkaocheng, having a proper magnitude, is selected as the corresponding identified star. I identified 2848 stars and 13 nebulosities out of 3083 objects in Yixiangkaocheng, and so the identification rate reached 92.80 per cent. I find that the magnitude classification system in Yixiangkaocheng agrees with the modern magnitude system. The catalogue includes dim stars, whose visual magnitudes are larger than 7, but most of these stars have Flamsteed designations. I find that the stars whose declination is lower than -30° have relatively larger offsets and different systematic behaviour from other stars. This indicates that there might be two different sources of stars in Yixiangkaocheng. In particular, I find that μ1 Sco and γ1 Sgr approximately mark the boundary between two different source catalogues. The observer's location, as estimated from these facts, agrees with the latitude of Greenwich where Flamsteed made his observations. The positional offsets between the Yixiangkaocheng stars and the Hipparcos stars are 0.6 arcmin, which implies that the source catalogue of stars with δ > -30° must have come from telescopic observations. Nebulosities in Yixiangkaocheng are identified with a few double stars, o Cet (the variable star, Mira), the Andromeda galaxy, ω Cen and NGC6231. These entities are associated with listings in Halley's Catalogue of the Southern Stars of AD 1679 as well as Flamsteed's catalogue of AD 1690.
[B2B-2-3] 14:40~15:00
[Invited] Historical Astronomy in National Astronomical Obervatory of Japan: Long-Term Variations of the Delay of the Earth Rotation
Kiyotaka Tanikawa (NationalAstrnomical Observatory of Japan, Japan) and Mitsuru Soma
Historical astronomy is defined to be a branch of science in which modern problems are studied using the ancient astrnomical records (Stephenson 1997). Depending on the characters of the records, the corresponding branches differ. Thus, for example, long term variations of the number of meteors and meteor showers may give us information on the life-time of mother comets and on the scattering rate of dust particles along the orbits of the comets (Ahn 2003; Yang et al. 2005). Historical supenovae give us information of the physics of supernova events (Stepehnson & Green 2002). A systematic study of the variations of brightness in the sequence of catalogs of stars extending more than one thousand years may reveal long-period variables (Fujiwara et al., 2004). It is well known that Earth's rotation decelerates secularly. This is because the angular momentum of the Earth-Moon system conserves and the Moon increases its orbital angular momentum by receding from the Earth. The secular change of Earth's rotation rate is accumulated to the delay of the time measured by the Earth rotation relative to the uniformly flowing time. This delay is called Delta T. The historical solar and lunar eclipses and the occultations of planets and stars by the Moon are the unique data for the determination of Delta T. The smoothed curves of Delta T has been obtained by Stephenson (1997) from historical (timed) solar and lunar eclipses. There are two unsolved problems related to the variations of Delta T. One is the inconsistency between the expected and observational secular trends. The observed trend of Delta T is smaller than the expected trend from the angular momentum conservation. This may be explained by the long-term, of the order of ten thousand years, climate changes. The second problem is the smoothness of the Delta T variations. Our target is to show the existence of short-term (less than few hundred years) variations of Delta T. In our talk, selecting and using records of solar eclipses of high quality for several periods of time between BC 700 and AD 1400, we give strong evidence of short-term variations of Delta T. In the talk, the method of analysis will be described graphically. Our result may provide an astronomical basis for the existence of the short-term climate variations.
[B2B-2-4] 15:00~15:15
An Identification of the Animal Paintings in the Hall of Bulls of the Lascaux Cave as the Constellations
Kwang-Tae Kim (Chungnam National University, Korea) and Young-Sik Kim
Since the discovery of the Lascaux cave in France in 1940, several attempts for identifications of the animal figures as constellations have been made. Among these are the Pleiades and the Taurus the most successful and well known to public to date. Among a total of 36 animals drawn some 17,000 year ago in The Great Hall of the Bulls, the four bulls (or aurochs) and the Unicorn are the dominant figures. We report here that all of these main animal figures are identified as the well known constellations such as the Orion+Canis Major+Canis Minor+Gemini, the Leo+Virgo, the Libra+Scorpio+Sagittarius, and that the dark animals as dark molecular clouds which form in line so spectacular along the 4th galactic quadrant from the Galactic center toward Canopus and Sirius. In this paper, we present the astronomical identification processes we made and some implications of the findings are discussed in relation to the Homo sapiens identity of Cro-Magnons in the Paleolithic Age.
Poster Session 15:15~15:30 Chairs: Il-Sung Nha Young Woon Kang (Sejong University)
Session: [B2B-3] S3 : Stars, Exoplanets and Stellar Systems Date: August 19, 2014 (Tuesday) Time: 14:00~15:30 Room: Room C (Room 104) Chair: Shengbang Qian (Yunnan Observatories)
[B2B-3-1] 14:00~14:20
[Invited] Recurrent Novae in the Multi-Wavelength Observations Era
G. C. Anupama (Indian Institute of Astrophysics, India)
Recurrent novae are a subclass of cataclysmic variable stars that have more than one recorded nova outbursts. The recurrent novae are a small but heterogeneous class of objects, with only about 10 such systems known in our own galaxy. A few recurrent novae are long period binaries with a red giant secondary, very similar to the symbiotic stars, while the others have a main sequence, or slightly evolved late type secondary, very similar to the classical novae. The recent outbursts of the recurrent novae, RS Oph (2006), U Sco (2010), T Pyx (2011) and V745 Sco (2013) have been studied in detail in all wavebands, and have provided several new and interesting insights into these rare objects. The properties of the recurrent novae based on multi-waveband observations will be discussed in this review.
[B2B-3-2] 14:20~14:35
Study of Superhumps in Recently Discovered SU UMa Dwarf Novae
Irina Voloshina (Sternberg Astronomical Institute, Russia) and Vladimir Metlov
Dwarf novae belong to the class of cataclysmic variables and represent the close binary systems on the late evolutionary stages. They consist of a white dwarf and a red dwarf which fills its Roche lobe and transfers mass to the white dwarf. The gas stream flows from the secondary to the primary white dwarf forming an accretion disk around it. Dwarf novae undergo outburst in semi-periodic intervals of time, when the brightness increases of 3 to 5 magnitude. SU UMa exhibit the special phenomenon, so-called «superhumps», on the light curve during superoutbursts (outbursts of larger amplitude and longer than normal ones). Superhumps represent an increase of the system brightness on the small part of the orbital light curve which repeated with the period a few percents longer than the orbital one. The amplitude of superhumps is around 0.1-0.3 mag. The orbital periods of these novae are about 80-180 min. The purpose of our study was an analysis of time- resolved photometry of program stars during superoutbursts which have been occurred in these systems during the last years. Our observations were carried out with CCD device on 50 cm and 60 cm telescopes of Sternberg Astronomical Institute Observatory in Crimea, mostly in R band. Superhumps were detected in the light curves of all systems. The amplitudes and periods of detected modulations were estimated. Evolution of superhumps was followed up and classification specified for all novae.
[B2B-3-3] 14:35~14:50
Investigation of Galactic Classical and Recurrent Novae with Ground-based Observations and the Solar Mass Imager (SMEI)
Farung Surina (Chiangrai Rajabhat University, Thailand), Michael F. Bode, Matthew J. Darnley, and Rebekah Hounsell
Classical novae (CNe) are interacting binary systems whose outbursts are powered by a thermonuclear runaway in accreted material on the surface of a white dwarf (WD). The secondary stars in such systems fill their Roche lobe and material is transferred onto the WD primary star via an accretion disk. Recurrent novae
(RNe) show many similarities to CNe, but have had more than one recorded outburst. RNe play an important role as one of the suspected progenitor systems of Type Ia supernovae which are used as primary distance indicators in cosmology. Thus, it is important to investigate the nature of their central binary systems to determine the relation between the parameters of the central system and outburst type, and finally ascertain the population of novae that might be available to give rise to the progenitors of Type Ia SNe. Low outburst amplitude is adopted as a criterion that may help distinguish RNe from CNe and was therefore used to select targets for observations from ground-based observations including the Liverpool Telescope and the Southern African Large Telescope and also the full-sky space-based archive of the Solar Mass Ejection Imager (SMEI). We found that at least four objects currently classified as CNe are suggested to be RNe candidates based on their quiescent spectra. We also Searched the SMEI archive for additional outbursts of bright CNe that might otherwise have been missed but did not find conclusive example.
[B2B-3-4] 14:50~15:05
Expansion Velocity and Spectroscopic Classification of Nova Delphini 2013
Rhisa Azaliah (Institut Teknologi Bandung, Indonesia), Hakim Luthfi Malasan, Gabriela Kezia Haans, and Saeful Akhyar
Low resolution spectrum of Nova Delphini 2013 (V339 Del) in the optical range have been obtained at Bosscha Observatory, Indonesia during its maximum light (V = 4.3). Spectrum was monitored and taken from August, 16th until 27th, 2013. The GAO-ITB RTS 20.3 cm telescope, SBIG DSS-7 spectrograph and SBIG ST-7 XE as the detector have been employed throughout the observations. The spectra show P-Cygni profiles in Balmer, Na'I'D and Fe II lines, from which we determined shell expansion velocity of 1421.66±139.18 km/s, 1227.54±121.57 km/s and 1402.86 km/s, respectively. Our spectroscopic observations followed spectrum evolution of V339 Del from the pre-maximum phase to early Orion phase. The characteristic of the nova Delphini 2013 resembles those of Fe II-type of nova.
Poster Session 15:05~15:30 Chairs: Irina Voloshina (Sternberg Astronomical Institute) Shengbang Qian (Yunnan Observatories)
Session: [B2B-4] S4 : Galaxies, AGN and Cosmology Date: August 19, 2014 (Tuesday) Time: 14:00~15:30 Room: Room D (Room 105~106) Chair: Atefeh Javadi (Institute for Research in Fundamental Science)
[B2B-4-1] 14:00~14:15
Super-Massive Black Hole Mass Scaling Relations
Alister W. Graham (Swinburne University of Technology, Australia), Nicholas Scott, and James Schombert
Feedback from AGN is thought to be a driving force in regulating the growth of galaxy bulges. For more than a decade it has been thought that this resulted in a linear relation generating a near constant (black hole)-to- (bulge) mass ratio of around 0.2%. Indeed, almost all of our models are matched to this constraint. However, new research with a larger, and better understood, galaxy sample has revealed that this linear relation only applies to high-mass galaxies/bulges likely formed from the simple additive dry merging of galaxies and their black holes. A significantly different relation exists between black holes and lower-mass galaxy bulges when gaseous processes (star formation, AGN fueling and feedback) are involved. In this regime, black hole growth scales quadratically with bulge growth. Some of the many implications of this dramatic revision will be briefly discussed, including: (i) galaxy/black hole formation theories; (ii) alleged pseudo-bulge detections; (iii) black hole mass predictions in other galaxies; (iv) predictions for space-based gravitational wave detections; and (v) evolutionary studies over different cosmic epochs.
[B2B-4-2] 14:15~14:30
Black Hole - Galaxy Scaling Relation and its Evolution
Jong-Hak Woo (Seoul National University, Korea)
The scaling relations between black hole mass and galaxy properties suggest a close connection between black hole growth and galaxy evolution, motivating a flood of theoretical and observational studies over the last decade. While studying the evolution of these relations over cosmic time provides valuable clues of the origin of the connection, a definitive resolution of this conundrum relies on understanding the slope and scatter of the local relations for AGNs. I will discuss the combined results from three-fold approach. First, accounting for the effect of the rotational broadening and inclination effect on the measured stellar velocity dispersion, I will discuss the local M-sigma relation using our new spectroscopy from Subaru and Palomar, particularly for pseudo-bulge galaxies, for which the spatially-resolved stellar kinematics were not previously available. Second, using a sample of ~100 AGNs in the local Universe, I will discuss the local AGN M-sigma relation, which provides a robust baseline of the BH mass scaling relations (MBH-sigma, MBH-L, MBH-M), based on the spatially-resolved Keck spectroscopy and SDSS imaging. Third, I will discuss the evolution of the scaling relations out to look-back times of 4-6 Gyrs and 8-10 Gyrs, using Keck spectra and HST images. The results indicate that 1) rotation effect can change the local M-sigma relation, particularly for disk-dominant galaxies. 2) Active galaxies follow the same scaling relations as inactive galaxies. 3) BH growth predates the final assembly of bulges, and the evolution is driven by disks being transformed into bulges. I will discuss the current limitations in studying the scaling relations using active galaxy samples.
[B2B-4-3] 14:30~14:45
Density Profiles for Chaplygin Gas Accretion Upon Black Holes : Moderately Differentiated Minima in Wind Branch
Ritabrata Biswas (Bengal Engineering and Science University Shibpur, India)
In this work we study the density change along the accretion and wind branches when modified Chaplygin gas is taken to be the accreting fluid. We get a high wind density very near to black hole while a low wind density far from the black hole. In modified Chaplygin gas accretion case a local minima in accretion-density is got which can be detected as the CENBOL.
[B2B-4-4] 14:45~15:00
On Small Nascent Galaxies in the Debris of Interacting Systems
C. Sengupta (Korea Astronomy and Space Science Institute, Korea), T. C. Scott, K. S. Dwarakanath, D. J. Saikia, and B. W. Sohn
Tidal interactions between gas rich galaxies can result in the displacement of large amounts of HI from the parent galaxy(s). Most of this stripped HI will eventually fall back into the potential of one or other of the interacting galaxies or be incorporated into the intra--group medium (IGM). But if the HI densities are sufficient and environmental conditions are favourable, self-gravitating bodies with masses typical of dwarf galaxies, called Tidal Dwarf Galaxies (TDG), may form within the tidally stripped gas. Observing these exotic objects, during their formation from gas/star debris provides a unique opportunity to investigate the processes governing formation and evolution of galaxies as well as the role of dark matter in their formation. To study in--situ star and TDG formation in tidal gas debris, we are carrying out an HI survey of a sample of interacting systems using the Giant Metrewave Radio Telescope (GMRT). In addition to the HI data from the GMRT, we are using the Sloan Digital Sky Survey (SDSS), Spitzer and Galaxy Evolution Explorer (GALEX) public data and images to understand the star/gas correlations in these objects. We present here results from three tidally interacting systems, Arp 181, Arp 202 and Arp 305. Each of these systems reveal interesting information on TDG formation. In Arp 181, a TDG is forming about 70 Kpc away from the parent galaxies, inside a massive gas cloud that shows signs of infalling HI. On the other hand, in Arp 305, the TDG candidate is observed between the parent galaxies. Due to its size and inclination, it is one of few TDG candidates suitable for dark matter studies. The TDG candidates in Arp 202 and Arp 305 are amongst a small number of TDGs which show extremely blue colours. We are studying these objects individually to understand their properties and whether they form a subcategory of ultra-blue TDGs
[B2B-4-5] 15:00~15:15
Molecular Gas and Radio Jet Interaction: A Case Study of the Seyfert 2 AGN M51
Satoki Matsushita (Academia Sinica Institute of Astronomy and Astrophysics , Taiwan), Dinh-V-Trung, Frederic Boone, Melanie Krips, Jeremy Lim, and Sebastien Muller
Recent high spatial resolution (~10 pc scale) molecular gas observations toward nearby active galactic nuclei (AGNs) revealed very disturbed features, such as jet-entrained or outflowing motions from AGNs or infalling motions toward AGNs, with little evidence of obscuring rotating disks or tori at this spatial scale. Seyfert 2 nucleus in the nearby galaxy M51 is one of them. We observed multiple CO transition lines and the HCN(1-0) line at ~1‖ (~34 pc) or higher resolution toward the Seyfert 2 nucleus of M51 using the IRAM Plateau de Bure Interferometer (PdBI) and the Submillimeter Array (SMA). All the images show very similar overall molecular gas distribution; there are two discrete clouds at the eastern and western sides of the nucleus, and the western cloud exhibits elongated distribution and velocity gradient along the radio jet. In addition, high HCN(1-0)/CO(1-0) brightness temperature ratio of about unity has been observed especially along the radio jet, similar to that observed at the shocked molecular gas in our Galaxy. This strongly indicates that the molecular gas along the jet is shocked, namely the radio jet and the molecular gas are interacting, and the jet is entraining both diffuse (CO) and dense (HCN) molecular gas outward from the circumnuclear region. This is the first clear imaging of the outflowing molecular gas entrained by the AGN jet, and showing the detailed physical status of outflowing molecular gas. Our results may also help to understand the nature of some of AGNs or ultra-/luminous infrared galaxies (U/LIRGs) that show outflowing molecular gas and/or high HCN/CO ratios at the nuclear regions.
[B2B-4-6] 15:15~15:30
BS2fit: New Tool for Analyzing Spectra and Color-Magnitude Diagrams of Galaxies and Clusters
Zhongmu Li (Dali University, China) and Caiyan Mao
We present a new tool for studying the spectral energy distributions (SEDs) and color-magnitude diagrams (CMDs) of galaxies and star clusters, BINARY STAR TO FIT (BS2fit). The feature of the tool is having taken the effect of binaries, stellar rotation, star formation history into account. It can determine many parameters, e.g., distance, extinction, binary fraction, rotational star fraction, and star formation history. Because more factors are included, BS2fit can potentially give new insight into the properties of galaxies and clusters.
Session: [B2B-5] S5 : Compact Objects, High Energy and Particle Astrophysics Date: August 19, 2014 (Tuesday) Time: 14:00~15:25 Room: Room E (Room 107) Chair: Chang-Hwan Lee (Pusan National University)
[B2B-5-1] 14:00~14:20
[Invited] Latest Results of MAXI (Monitor of All-sky X-ray Image)
Tatehiro Mihara (RIKEN, Japan)
MAXI is a Japanese X-ray all-sky monitor mounted on the International Space Station (ISS). It has been scanning the whole sky since 2009 in every 92 minutes of ISS rotation. MAXI has two kinds of instruments: Gas Slit Camera (GSC) and Solid-state Slit Camera (SSC). GSC is a slit camera using Xe-gas proportional counter, and SSC is one using 32 X-ray CCD chips. By the real-time nova-search program, MAXI can find a transient quickly. MAXI issued 133 to Astronomers Telegram and 44 to Gamma-ray burst Coordinated Network so far. In the 4.5 years of observation MAXI discovered 6 of 12 new black holes. The long-term behaviors of MAXI black holes can be classified into two types of the outbursts; 3 fast-rise exponential-decay and 3 fast-rise and flat-top. The cause of types is still unknown. The slit camera is suitable to accumulate the data for a long time. MAXI issued the 37-month catalog detecting 500 sources above ~0.6 mCrab in 4-10 keV in |b| > 10 degrees. SSC with X-ray CCD has detected diffuse soft X-rays in the all-sky, such as Cygnus super bubble, as well as it found a fast soft X-ray nova MAXI J0158-744. The overall shapes of outbursts in Be X- ray binaries are well observed with GSC. There are two kinds of outbursts, a normal outburst and a giant outburst. The peak dates of the subsequent giant outbursts of A0535+26 repeated in a different period from the orbital one. The Be stellar disk is considered either to have a precession motion or a distorted shape (Nakajima et al. 2014). The long-term behaviors of Low Mass X-ray Binaries (LMXB) containing weakly magnetized neutron stars are investigated. Transient LMXBs (Aql X-1 and 4U 1608-52) repeats outbursts in every 200-1000 days. The luminosity changes 1.5 orders of magnitude, which is understood by the limit-cycle of hydrogen ionization state in outer accretion disk. The accretion rate from the companion star would be constant. However, the limit cycle produces a change of the accretion rate inward. The spectral state during an outburst changes from hard-state, soft-state, and then hard-state again. This state is created by the inner part of the accretion disk, depending on the accretion rate at there. Moreover, Aql X-1 and 4U 1608-52 have the third state, very dim state. We interpret it as the propeller effect in the unified picture of LMXB by Matsuoka and Asai (2013). Cir X-1 is a peculiar source, in the sense that the long-term behavior is not like typical LMXBs. The nature comes from the binary type, Be binary with a weakly magnetized neutron star. MAXI/GSC observed 21 outbursts from Cir X-1. In seven outbursts, we found sudden luminosity decreases at periastron. It cannot be explained by either a decay of an outburst, nor the propeller effect. The stripping effect by the clumpy stellar wind of the companion star at an outer accretion disk radius is possible (Asai et al. 2014).
[B2B-5-2] 14:20~14:40
[Invited] Particle Acceleration at Supernova Remnant Shocks
Hyesung Kang (Pusan National University, Korea)
Most of high energy cosmic rays (CRs) are thought to be produced by diffusive shock acceleration (DSA) at supernova remnants (SNRs) within the Galaxy. Plasma and MHD simulations have shown that the CR streaming instability excites MHD waves and amplifies the turbulent magnetic field by orders of magnitude in the precursor of strong shocks. In this study we demonstrate that the time-dependent evolution of the self- amplified magnetic fields, Alfvénic drift, and escape of the highest energy particles affect the energy spectra of accelerated protons and electrons at SNR shocks. The maximum energy of CR protons can be boosted
significantly only if the scale height of the magnetic field precursor is long enough to contain the diffusion lengths of the particles of interests. The source spectrum of PeV protons at SNRs is likely to be flatter than E- 2, if order of 10 % of the explosion energy is transferred to the CR energy. The spectral cutoffs of nonthermal radiation spectra in X-ray and -ray emitted by CR protons and electrons are regulated by the evolution of the highest energy particles, which are injected at the early phase of SNRs. Thus detailed understandings of nonlinear wave-particle interactions and time-dependent history of DSA are crucial in testing the SNR hypothesis for the origin of Galactic cosmic rays.
[B2B-5-3] 14:40~14:55
Particle Acceleration and Diffusion in Supernova Remnants in a Multiphase Interstellar Medium
Soonyoung Roh (Nagoya University, Korea), Shu-ichiro Inutsuka, and Tsuyoshi Inoue
Supernova remnants (SNRs) are one of the most powerful astrophysical events and are thought to be the dominant source of Galactic cosmic rays (CRs). A recent report by Funk et al. (2013) has shown an unequivocal signature of pion-decay in the gamma-ray spectra of SNRs. This provides strong evidence that high energy protons are accelerated in SNRs. On the other hand, Fukui et al. (2012) showed that pion decay from protons dominates in emission from SNR RX J1713 based on the spatial correlation of gamma-rays and molecular line emission. The actual gamma-ray emission from pion decay should depend on the diffusion of CRs in a multiphase interstellar medium with molecular clouds (Inoue et al. 2012). In order to quantitatively describe the diffusion of high energy CRs from acceleration sites, we have performed test particle numerical simulations using three-dimensional magnetohydrodynamics (MHD) simulation data provided by Inoue et al. (2012). In this presentation, we calculate realistic diffusion coefficients of cosmic rays in simulated SNRs, and discuss the possible implications for X-ray and gamma-ray observations.
[B2B-5-4] 14:55~15:10
Strong Influence of the Galactic Magnetic Field on the Propagation of Ultra-high Energy Cosmic Rays
Jihyun Kim (Ulsan National Institute of Science and Technology, Korea), Hang Bae Kim, and Dongsu Ryu
The galactic magnetic field (GMF) affects the propagation of ultra-high energy cosmic rays (UHECRs) from sources to us. Here we examine the influence of the GMF with the independence of their sky distribution on the galactic latitude, l. We analyze the correlation between the arrival direction (AR) of UHECRs observed by the Pierre Auger Observatory and the large-scale structure of the universe in the regions of sky divided by l. Specifically, we compare the AR distribution of observed UHECRs to that of mock UHECRs generated from a source model constructed with active galactic nuclei. Our source model has the smearing angle as a free parameter that reflects the deflection angle of UHECRs from sources. The results show a trend that larger smearing angles are required for the observed distribution of UHECRs in lower galactic latitude regions. We obtain, for instance, the best-fit smearing angle 9° and 84° in the high galactic latitude, -90°< l < -60°, and in the low galactic latitude, -30°< l <30°, respectively. For all sky region, the best-fit smearing angle is 54°. These angles are larger than the expected value of a few degrees for proton, implying that UHECRs would be composed of heavier nuclei.
[B2B-5-5] 15:10~15:25
Spider Invasion Across the Galaxy
David C. Y. Hui (Chungnam National University, Korea)
The nature of the exotic stellar corpses which reincarnate by consuming their companion will be reviewed. Apart from sucking life from their partners, they are actually eating the doomed companions away by their deadly and powerful particle/radiation beams. Such situation resembles that a female ―black widow‖ spider (and their Australian cousin ―redbacks‖) that eats its mate after mating. These celestial zombies are called – Millisecond pulsars. In this talk, I will focus on the effort of Fermi Asian Network (FAN) in exploring these intricating objects over the last five years.
Session: [B2B-6] S6 : Observing Facilities and International Collaborations Date: August 19, 2014 (Tuesday) Time: 14:00~15:30 Room: Room F (Room 108) Chair: Masanori Iye (National Astronomical Observatory of Japan)
[B2B-6-1] 14:00~14:20
[Invited] The Next-Generation Infrared Astronomy Mission SPICA under the New Framework
Takao Nakagawa (Institute of Space and Astronautical Science/JAXA, Japan), Hiroshi Shibai, Takashi Onaka, Hideo Matsuhara, Hidehiro Kaneda, Yasuhiro Kawakatsu, and SPICA Team
We present the current status of SPICA (Space Infrared Telescope for Cosmology and Astrophysics), which is a mission optimized for mid- and far-infrared astronomy with a cryogenically cooled 3m-class telescope. SPICA is expected to achieve high spatial resolution and unprecedented sensitivity in the mid- and far- infrared, which will enable us to address a number of key problems in present-day astronomy, ranging from the star-formation history of the universe to the formation of planets. We have carried out the ―Risk Mitigation Phase‖ activity, in which key technologies essential to the realization of the mission have been extensively developed. Consequently, technical risks for the success of the mission have been significantly mitigated. Along with these technical activities, the international collaboration framework of SPICA had been revisited, which resulted in larger contribution of ESA than that in the original plan. To enable the ESA participation under the new framework, a SPICA proposal to ESA is under consideration as a medium-class mission under the framework of the ESA Cosmic Vision. The target launch year of SPICA under the new framework is mid 2020s
[B2B-6-2] 14:20~14:40
[Invited] ASTRO-H International X-ray Observatory
Motohide Kokubun (Institute of Space and Astronautical Science/JAXA, Japan), Tadayuki Takahashi, and the ASTRO-H Collaboration
The ASTRO-H mission is an international X-ray observatory which is scheduled to be launched in 2015 by the H-IIA rocket of JAXA. The spacecraft carries four kinds of six instruments equipped with four X-ray telescopes, which enable us to investigate the physics of hot and non-thermal universe with an unprecedented high energy resolution, simultaneously covering a wide energy range of 0.3 to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3–12 keV with an energy resolution better than 7 eV, two sets of hard X-ray telescopes and imaging spectrometers covering 5–80 keV, a wide-field X-ray CCD camera sensitive over 0.4–12 keV, and two Compton-camera type soft gamma-ray detectors, sensitive in the 40–600 keV band. The scientific goal of the mission covers a wide variety of important science themes, from fundamental physics observed in extreme conditions around the compact objects like neutron stars and black holes, to the history of formation and evolution of the largest structures in our universe. This talk will represent an overview of the mission, basic technologies developed and used, the current status of the production, in addition to prospects of the astrophysical impacts which are expected to be achieved by the capabilities of ASTRO-H.
[B2B-6-3] 14:40~15:00
[Invited] Quantifying Dark Molecular Gas (DMG)
Di Li (National Astronomical Observatories, China), Carl Heiles, Duo Xu, and Zhichen Pan
Interstellar gas is the building block of stars and galaxies. A significant quantity of interstellar gas cannot be traced by either CO or HI emission and has been dubbed "dark das". Understanding the nature of dark gas is a critical step in understanding the full lifecycle of the Milky Way and evolution of galaxies. The collaboration of FAST and other giant telescopes and interferometers in the world, such as Arecibo, ATCA, ALMA, and JVLA, will provide us a platform to study dark gas in high sensitivity and resolution. We plan to study the abundance and distribution of dark gas, in order to comprehensively understand Milky Way interstellar medium and the formation of stars.
[B2B-6-4] 15:00~15:15
[Invited] CFHT Status Report and Future Plans
Doug Simons (Canada-France-Hawaii Telescope, USA)
After a brief summary of recent metrics illustrating the scientific success of CFHT, the future of the Observatory is described through various initiatives designed to broaden the CFHT partnership, develop new capabilities, and take steps toward the replacement of CFHT with a powerful new facility (ngCFHT) dedicated to highly multiplexed wide-field spectroscopy. CFHT, in the context of the evolving landscape on Mauna Kea will also be discussed, as CFHT positions itself among a backdrop of some older facilities possibly being decommissioned while new Mauna Kea facilities are on the planning horizon.
[B2B-6-5] 15:15~15:30
The Australia Telescope National Facility
Philip Edwards (CSIRO Astronomy & Space Science, Australia) and Naomi McClure-Griffiths
The Australia Telescope National Facility (ATNF) is an open access radio astronomy observatory operated by Australia‘s Commonwealth Scientific and Industrial Research Organisation (CSIRO). The ATNF consists of the Parkes 64m radiotelescope, the Australia Telescope Compact Array, and the Mopra 22m radiotelescope. The Australian Square Kilometer Array Pathfinder (ASKAP), a new wide-field array of thirty-six 12m antennas, is currently being commissioned and will commence early science in 2015. In addition, under the host country agreement with NASA, some access is provided to the Tidbinbilla 70m and 34m antennas. Approximately 5% of the time on these facilities is used for high angular resolution Very Long Baseline Interferometry (VLBI) observations. Observing time on ATNF telescopes is open to astronomers from any country, on the scientific merits of the proposed research. The ATNF has a large international user community, with good representation from the Asia-Pacific region. In this presentation, each element of the National Facility will be introduced and recent developments highlighted. The Parkes radio-telescope has a suite of receivers operating at frequencies between 700 MHz and 22 GHz. It has state-of-the-art digital filterbanks and correlators for pulsar, spectral line and continuum observations. Over the last 4 years Parkes has undergone a number of upgrades and improvements, which have enabled completely remote operations. The Australia Telescope Compact Array is an array of six 22m antennas that operate between 1.1 and 105 GHz. The Compact Array Broadband Backend (CABB) upgrade in 2008 has enabled two 2-GHz bandwidth, dual polarization, channels to be recorded with spectral resolutions ranging from 64 MHz to 0.5 kHz. The array is reconfigured every few weeks, cycling through the 17 standard array configurations with maximum baselines between 90m and 6km. The Mopra radio-telescope is used primarily in the 16—27 GHz, 30—50 GHz and 76—117 GHz bands. The MOPS spectrometer provides a wideband mode, with four 2.2GHz bands each with 8192 channels in both polarisations, and 16 narrowband ―zooms‖ giving 33 kHz wide channels. Mopra is currently operating under an externally funded model with the majority of the time allocated to the funding consortia, and with ~5 weeks available each winter for open access under the standard proposal process. The Long Baseline Array combines the Parkes, ATCA and Mopra facilities with the Hobart and Ceduna telescopes of the University of Tasmania for VLBI observations. Telescopes at Tidbinbilla, Warkworth (New Zealand), Hartebeesthoek (South Africa), and a single ASKAP dish also participate on occasions. The LBA operates in the standard radioastronomy bands between 1.4 and 22 GHz. The newest element of the ATNF is the 36 antenna, wide- field ASKAP array. ASKAP is being outfitted with Phased Array Feeds, each covering 30 square degrees of sky with a 300MHz bandwidth between 700MHz and 1.8 GHz. The array is currently being commissioned, providing experience in the beamforming and calibration of the novel feeds. In the first years of operation it is expected ~75% of the observing time will be dedicated to a number of large survey projects.
Session: [B2C-1] S1 : Solar System and Sun-Earth Interactions Date: August 19, 2014 (Tuesday) Time: 16:00~17:30 Room: Room A (Room 101~102) Chair: Saku Tsuneta (Japan Aerospace Exploration Agency)
[B2C-1-1] 16:00~16:15
Which Cone Type is Closer to 3-D CME Structures?
Hyeonock Na (Kyung Hee University, Korea), Yong-Jae Moon, Harim Lee, Soojeong Jang, and Jae-Ok Lee
Recently, CME cone models are widely used for inferring three dimensional structures of CMEs and their propagation through the heliosphere, especially for the input parameters of CME propagation models. However, there has been no observational test which cone type is closer to CME 3-D structures. In this study, we investigate which cone model is proper for halo CME morphology using 35 CMEs which are identified as halo CMEs by one spacecraft and as limb CMEs by the other ones. These CMEs were taken by SOHO/LASCO and STEREO/SECCHI during the period from 2010 December to 2011 June when two spacecraft were separated by 90° ± 10°, which allows us to directly estimate their angular widths from observations. From geometrical parameters of these CMEs such as their front curvature, they are classified into two groups: shallow cone CME whose curvature radius is equal to the distance of CME front from the center of the Sun, and full-cone CME, whose front has a semi-circle shape. Our results show that most of the events are closer to the full cone type than the shallow cone type.
[B2C-1-2] 16:15~16:30
Magnetohydrodynamic Modeling of the Solar Flare Based on the Photospheric Magnetic Field
Satoshi Inoue (Kyung Hee University, Korea), Keiji Hayashi, and Gwangson Choe
Solar flares and coronal mass ejections (CMEs) are biggest explosions in our solar system and primarily driver sources causing the large space storm in our geospace. Therefore, the understanding of these fundamental processes is important extremely to build up the space weather forecast. These are widely considered as sudden liberation of magnetic energy in the solar corona; nevertheless, we could not reach on a common understanding yet. In order to clarify them, in this study we perform a magnetohydrodynamic (MHD) simulation combined with photospheric magnetic field before X2.2-class flare taking place in the solar active region 11158, observed by Solar Dynamics Observatory (SDO). We first extrapolate a three- dimensional (3D) coronal magnetic field under the Nonlinear Force-Free Field (NLFFF) approximation based on the photospheric magnetic field to understand its 3D and physical properties. Next we perform a MHD simulation using the NLFFF prior to the flare to clarify the dynamics during the flare. As a result, we found that the NLFFF has strongly twisted field lines; most of them are in the range from half- turn to one turn twist, being resided above the polarity inversion line. Because the most of these strongly twisted lines disappear after the flare, consequently the twisted field lines having more than half-turn twist play an important role on causing the large flare. On the other hand, we found that the NLFFF never shows the dramatic dynamics seen in observations, i.e., it is in stable state against the perturbations. However, the MHD simulation shows that when the strongly twisted lines are formed close to the neutral line, which are produced via tether-cut reconnection in the twisted lines of the NLFFF, consequently they erupt away from the solar surface via the complicated reconnection. In addition to this the dynamical evolution of these field lines reveals that at the initial stage the spatial pattern of the footpoints caused by the reconnection of the twisted lines appropriately maps the distribution of the observed two-ribbon flares. Interestingly, after the flare the reconnected field lines convert into the structure like the post flare loops, which is analogous to EUV image taken by SDO. Eventually, we found that the twisted lines exceed a critical height at which the flux tube becomes unstable to the torus instability. These results illustrate the reliability of our simulation and also provide an important relationship between flare-CME dynamics. We will also discuss that how much twists
are needed to lunch from the solar surface, and the reconnection dynamics while the twisted lines are ascending.
[B2C-1-3] 16:30~16:45
Flux Rope Eruption above Kinked Filament Observed by SDO/AIA and STEREO
Pankaj Kumar (Korea Astronomy and Space Science, Korea) and K.S. Cho
We present multiwavelength observations of a C-class limb flare associated with the eruption of a flux rope. The high resolution images recorded by SDO/AIA 304, 1600 Å and Hinode/SOT Hα show the activation of a mini-filament associated with kink instability and the onset of a C-class flare near the southern leg of the filament. The filament showed unwinding motion of the northern leg and apex in the counterclockwise direction and failed to erupt. A twisted flux-rope was appeared during magnetic reconnection taking place above the kinked filament. The flux rope rises slowly (∼100 km/s ) producing a rather big twisted structure possibly by reconnection with the surrounding sheared magnetic fields within ∼15-20 minutes, and showed an impulsive acceleration reaching a height of about 80–100 Mm. This study focuses on the formation and eruption of the flux rope structure observed in the hot AIA channels.
[B2C-1-4] 16:45~17:00
Wave Properties of a Pore Observed by SDO HMI and AIA on 2013 March 11
Su-Chan Bong (Korea Astronomy and Space Science Institute, Korea), Kyung-Suk Cho, Eun-Kyung Lim, Il- Hyun Cho, Yeon-Han Kim, and Young-Deuk Park
We report the wave properties of a pore observed by HMI (Helioseismic and Magnetic Imager) and AIA (Atmospheric Imaging Assembly) onboard SDO (Solar Dynamics Observatory) on 2013 March 11. The pore is about 5 arcsec in diameter and well isolated from the other pores or spots. We calculated the weighted mean values of intensity, line-of-sight magnetic field, and line-of-sight velocity inside the pore as well as the area. We found strong 4.5 min oscillation in the photospheric HMI intensity but could not find prominently enhanced power at the corresponding period in the magnetic field, velocity, and area. In AIA, we could see strong oscillation at 5.5 min period in the low chromospheric 160 nm and 170 nm intensity, and at 2.5 min period in the upper chromospheric 30.4 nm intensity. This is in contrast with the conventional cut-off frequency explanation that interior waves with frequencies higher than the cut-off frequency propagate through the upper atmosphere.
[B2C-1-5] 17:00~17:15
Correlated Multipath Effects between Distant Radio Telescopes
P. N. Diep (Vietnam Astrophysics Training Laboratory, Vietnam), N. T. Phuong, P. Darriulat, P. T. Nhung, P. T. Anh, P. N. Dong, D. T. Hoai, and N. T. Thao
A multipath mechanism similar to that used in Australia sixty years ago by the Sea-cliff Interferometer is shown to generate correlations between the periods of oscillations observed by two distant radio telescopes pointed to the Sun. The oscillations are the result of interferences between the direct wave detected in the main antenna lobe and its reflection on ground detected in a side lobe. A model is made of such oscillations in the case of two observatories located at equal longitudes and opposite tropical latitudes, respectively in Ha Noi (Viet Nam) and Learmonth (Australia), where similar radio telescopes are operated at 1.4 GHz. Simple specular reflection from ground is found to give a good description of the observed oscillations and to explain correlations that had been previously observed and for which no satisfactory interpretation, instrumental or other, had been found.
[B2C-1-6] 17:15~17:30
Relationship between Metric Type II Solar Radio Bursts and Coronal Mass Ejections
Kyungsuk Cho (Korea Astronomy and Space Science Institute, Korea)
Metric type II solar radio bursts are known radio signatures of coronal shocks. Since the first discovery of the
metric type II burst by Payne-Scott, Yabsley, and Bolton (1947), the debate on the origin (solar flare and/or coronal mass ejection) of the type II bursts has continued. By comparing kinematics of m-type II shocks with those of CMEs observed by SOHO/LASCO C1 & C2, MLSO/MK4, STEREO/COR1, and SDO/AIA, I have investigated the relationship between the type II shocks and CMEs. I found that CMEs could be main source of type II bursts, and suggested that type II bursts are generated in two sites: either at the CME nose or at the CME-streamer interaction site. I will review my studies on the relationship between CMEs and metric type II radio bursts.
Session: [B2C-2] S2 : Interstellar Matter, Star Formation and the Milky Way Date: August 19, 2014 (Tuesday) Time: 16:00~17:25 Room: Room B (Room 103) Chair: Bon-Chul Koo (Seoul National University)
[B2C-2-1] 16:00~16:20
[Invited] A Global View of Star Formation in the Milky Way
Karl M. Menten (Max-Planck-Institute for Radio Astronomy, Germany)
Stars with more than about ten solar masses dominate galactic ecosystems. Understanding the circumstances of their formation is one of the great challenges of modern astronomy. The spectacular HII regions they excite delineate the spiral arms of galaxies such as our own when seen face on – making it clear that star formation and Galactic structure are intimately related. We report on an ambitious program that consists of a powerful multi-pronged approach to study star formation over the whole Milky Way. Using VLBI observations of maser sources associated with young protostars, we are measuring distances by trigonometric parallax to most of the dominant star forming regions in the Galaxy, which will reveal its spiral structure and yield improved values of the rotation parameters and are crucial for determinations of luminosities and masses. Submillimeter emission from dust mapped by ATLASGAL, the APEX Telescope Large Area Survey of the Galaxy delivers the locations of deeply embedded protostars and protoclusters and their masses. In a comprehensive follow-up program we are studying the state of excitation, chemistry and kinematics of their gaseous content. At longer, radio wavelengths, in a very sensitive survey with the newly expanded Karl G. Jansky Very Large Array (JVLA) we find masers and hyper- and ultracompact HII regions, pinpointing the very centers of the earliest star-forming activity. We are also studying the infrared emission from more developed massive star clusters, deriving distances with the classic spectro-photometric method for the first time adapted to an extensive IR dataset and properly calibrated with trigonometric parallaxes. Our synoptic approach is using the world‘s premier observatories to create a coherent, unique dataset with true legacy value for a global perspective on star formation in our Galaxy.
[B2C-2-2] 16:20~16:40
[Invited] New Frontiers of Magnetized Turbulence in the Multiphase Interstellar Medium
Blakesley Burkhart (University of Wisconsin Madison, USA) and Alex Lazarian
The current paradigm of the ISM is that it is a multiphase turbulent environment, with turbulence affecting many important processes. For the ISM this includes star formation, cosmic ray acceleration, and the evolution of structure in the diffuse ISM. This makes it important to study interstellar turbulence using the strengths of numerical studies combined with observational studies. I shall discuss progress that has been made in the development of new techniques for comparing observational data with numerical MHD simulations in the molecular medium, in neutral gas as traced by HI, and warm ionized gas as traced by synchrotron polarization.
[B2C-2-3] 16:40~16:55
Cosmic Fountains Reveal the Birth and Death of Stars
Lisa Harvey-Smith (CSIRO Astronomy & Space Science, Australia), Jimi Green, Steven Longmore, Cormac Purcell, and Andrew Walsh
Water masers are bright, narrow-band sources of non-thermalradio emission that are generated in shocked molecular gas. They arecommonly found in regions surrounding young massive star formation andpost-AGB
stars with collimated outflows that are transitioning intoplanetary nebulae. As narrow spectral line sources, masers are extremelyuseful for measuring the structure and motion of gas in these regions. We have used multi-frequency astronomical data to study ten Galactic watermasers that have an extremely high (200-400 km/s) spread in radialvelocity, indicating the presence very high-velocity outflows. Thesemasers were selected from the HOPS survey using theMopra radio telescope and re-observed at higher resolution using theAustralia Telescope Compact Array. In nine of the ten cases, the ATCA data resolved the outflow andmulti-frequency dataenabled us to identify the state of stellar evolution of the region.Seven of the sources were identified as young stellar objects; two aspre-planetary nebulae and one remains unidentified. In this talk, I will present imagesof these fascinating sources, discuss the impact of this study on ourunderstanding of masers as signposts of stellar evolution and suggestfuture work.
[B2C-2-4] 16:55~17:10
Inflows in Massive Star Formation Regions
Yuefang Wu (Peking University, China), and Tie Liu
How high-mass star form remains unclear currently. Calculation shows that the radiation pressure of a forming star can halt spherical infall, preventing its further growth when it reaches 8 M⊙. Two major theoretical models on the further growth of such stars were proposed. One model suggests the mergence of less massive stellar objects, and the other is still through accretion but with the help of disk or outflow. Inflow motions are the key evidence of how forming stars further grow. Recent development in technology has boosted the search of inflow motion. A number of high-mass collapse candidates were obtained with single dish observations, mostly shown in ―blue profile‖. Physical parameters and correlations between inflow velocity and source masses were obtained and analyzed. The infalling signatures seem more common in regions with developed radiation than in younger cores, which opposes the theoretical prediction and is also very different from that of low – mass star formation. Interferometer studies so far confirm such tendency with more obvious ―blue profile‖ or inverse P Cygni profile. Results seem to favor the accretion model. However, the direct evidence for the collapse processes is in monolithic or in competitive deeds to be searched. Future work is also needed to distinguish among infall, rotation and outflow regions, and to resolve the core peak and the young stellar objects.
[B2C-2-5] 17:10~17:25
ALMA Results of the Pseudodisk, Rotating Disk, and Jet in the Very Young Protostellar System HH 212
Chin-Fei Lee (Academia Sinica Institute of Astronomy and Astrophysics, Taiwan), Naomi Hirano, Qizhou Zhang, Hsien Shang, Paul T. P. Ho, and Ruben Krasnopolsky
HH 212 is a nearby (400 pc) Class 0 protostellar system showing several components that can be compared with theoretical models of core collapse. We have mapped it in the 350 GHz continuum and HCO+ J = 4–3 emission with ALMA at up to ∼ 0.4‖ resolution. A flattened envelope and a compact disk are seen in the continuum around the central source, as seen before. The HCO+ kinematics shows that the flattened envelope is infalling with small rotation (i.e., spiraling) into the central source, and thus can be identified as a pseudodisk in the models of magnetized core collapse. Also, the HCO+ kinematics shows that the disk is rotating and can be rotationally supported. In addition, to account for the missing HCO+ emission at low- redshifted velocity, an extended infalling envelope is required, with its material flowing roughly parallel to the jet axis toward the pseudodisk. This is expected if it is magnetized with an hourglass B-field morphology. We have modeled the continuum and HCO+ emission of the flattened envelope and disk simultaneously. We find that a jump in density is required across the interface between the pseudodisk and the disk. A jet is seen in HCO+ extending out to ∼500 AU away from the central source, with the peaks upstream of those seen before in SiO. The broad velocity range and high HCO+ abundance indicate that the HCO+ emission traces internal shocks in the jet. In summary, our ALMA results show that HH 212 is a really textbook case for demonstrating the processes of in the early phase of star formation.
Session: [B2C-3] S3 : Stars, Exoplanets and Stellar Systems Date: August 19, 2014 (Tuesday) Time: 16:00~17:25 Room: Room C (Room 104) Chair: G. C. Anupama (Indian Institute of Astrophysics)
[B2C-3-1] 16:00~16:20
[Invited] The Dust Production by Evolved Stars in the Magellanic Clouds
F. Kemper (Academia Sinica Institute of Astronomy and Astrophysics, Taiwan)
Within the context of the hugely successful SAGE-LMC and SAGE-SMC surveys, Spitzer photometry observations of the Large and Small Magellanic Clouds have revealed millions of infrared point sources in each galaxy. The brightest infrared sources are generally dust producing and mass-losing evolved stars, and several tens of thousands of such stars have been classified. After photometrically classifying these objects, the dust production by several kinds of evolved stars -- such as Asymptotic Giant Branch stars and Red Supergiants -- can be determined. SAGE-Spec is the spectroscopic follow-up to the SAGE-LMC survey, and it has obtained Spitzer-IRS 5-40 micron spectroscopy of about 200 sources in the LMC. Combined with archival data from other programs, observations at a total of ~1000 pointings have been obtained in the LMC, while ~250 IRS pointings were observed in the SMC. Of these, a few hundred pointings represent dust producing and mass-losing evolved stars, covering a range in colors, luminosities, and thus mass-loss rates. Red Supergiants and O-rich and C-rich AGB stars -- the main dust producers -- are well represented in the spectroscopic sample. In this talk I will review what we know about the mineralogy of dust producing evolved stars, and discuss their relative importance in the total dust budget.
[B2C-3-2] 16:20~16:40
[Invited] Observational Studies of Evolved Stars Using the KVN
Se-Hyung Cho (Korea Astronomy and Space Science Institute, Korea) and KVN Evolved Star Sub-Working Group Members
The Korean VLBI Network (KVN) as a world-first multi-frequency VLBI system is operated at four bands of 22, 43, 86, and 129 GHz simultaneously. Using this advantage of KVN, we have performed simultaneous observations of H2O and SiO maser lines in order to investigate spatial structure and dynamical effect from SiO to 22 GHz H2O maser regions in AGB stars and characteristics of both maser emission at the evolutionary process from AGB to post-AGB star.At the first stage of KVN operation, we have performed single dish surveys and monitoring observations. After confirming the performance of VLBI network since 2013, we have also performed VLBI observations toward selected targets based on single dish results. Here we present the main results of single dish observations toward about 1000 evolved stars together with several VLBI results. Firstly, main results of single dish are summarized as following. The intensities of SiO masers are stronger than those of H2O masers in most evolved stars and at most optical phases. However, the peak intensities of H2O are stronger than those of SiO around maximum phases in several stars. One-way and double peaks of H2O maser emission which may be associated with an asymmetric outflow appear in large percentage at late stage of AGB evolution and at post-AGB stage compared with young AGB stage. In addition, SiO v=2 only masers showed the similar tendency. Different detection rates between SiO and H2O masers also appear at post-AGB stage Secondly, VLBI results are summarized as following. The fringe detection rates at one epoch obtained from simultaneous fringe survey of 41 evolved stars at 4 bands were 62% at 22 GHz, 83% at 43 GHz, 54% at 86 GHz, and 17% at 129 GHz bands, respectively. For VY CMa and IK Tau, 4 band images were obtained simultaneously. Based on these observational results, we plan to start KVN key science program in the field of evolved stars from this autumn.
[B2C-3-3] 16:40~16:55
Japanese VLBI Network Mapping of SiO v=2 and v=3 J=1-0 Masers around Evolved Stars
M. Oyadomari (Kagoshima University, Japan) and H. Imai
We present results of simultaneous Very Long Baseline Interferometric (VLBI) observations of v=2 and v=3 J=1-0 maser emission of SiO towards 12 long-period variable stars using the VLBI Exploration of Radio Astrometry (VERA) and the 45 m telescope of Nobeyama Radio Observatory (NRO).The v=3 masaer emission was detected in 5 stars and image synthesis with v=2 and v=3 masers was obtained in 4 stars: W Hya, WXPsc, T Cep and R Leo. The maser distribution of v=3 maser emission was clearly different between T Cep and others. We suggest that the v=3 maser of T Cep was predominantly excited in H2O overlapping pumping mechanism, others was excited in collisional pumping mechanism.
[B2C-3-4] 16:55~17:10
Period Variation of EROS Eclipsing Binary Systems in the Large Magellanic Cloud
Pakakew Rittipruk (Sejong University, Korea), Young-Woon Kang, and Kyeongsoo Hong
We investigated the period variation for 79 eclipsing binary systems using 20 years (1990-2009) EROS, Macho, and OGLE survey observations. We discovered 9 apsidal motions, 8 Mass Transfers, 5 Period increasing and decreasing systems, 12 Light-Travel-time effects, 5 eccentric systems and other 40 systems show no period variation. We select 4 representative eclipsing binary systems which are Eros1052 for apsidal motion, Eros1056 for Mass transfer, Eros1039 for period decreasing systems and Eros1037 for Light-Travel- time effect. rd We determine the period variation rate (dP/dt), orbital parameters of the 3 body (e3, ω3, f(m3), P3, T3), apsidal motion parameters (dω/dt, U, Ps, Pa, e) and apsidal motion period by analyzed light curves and O-C diagrams.
[B2C-3-5] 17:10~17:25
Kinematical Properties of Planetary Nebulae with WR-type Nuclei
A. Danehkar (Macquarie University, Australia), W. Steffen, and Q. A. Parker
We have carried out internal field unit (IFU) spectroscopy of Hα and [N II] emission lines for a sample of Galactic Planetary Nebula (PNe) with Wolf-Rayet (WR) stars and weak emission-line stars (wels). Based on the spatially resolved observations, combined with archival imaging, we have determined their kinematic structures. Comparing the observed velocity maps provided by the IFU observations with those produced by morpho-kinematic models allowed us to exclude the projection effect from the nebula's appearance and identify the morphology of most PNe, apart from the compact objects. Our results indicate that these PNe have axisymmetric morphologies, either bipolar or elliptical. In many cases the associated kinematic maps for the PNe around hot WR central stars also reveal the presence of so-called fast low-ionization emission regions (FLIERs). However, it is as yet unknown which mechanism produces axisymmetric morphologies and how the density and velocity of FLIERs contrast sharply with the main body of the nebula. Deeper spectroscopy of their central stars will develop a better understanding of the mechanisms shaping their kinematic structures.
Session: [B2C-4] S4 : Galaxies, AGN and Cosmology Date: August 19, 2014 (Tuesday) Time: 16:00~17:30 Room: Room D (Room 105~106) Chair: Jong-Hak Woo (Seoul National University)
[B2C-4-1] 16:00~16:20
[Invited] Merger Relics in Galaxy Clusters
Sukyoung K. Yi (Yonsei University, Korea)
According to the classical dynamics, galaxy mergers are expected to be extremely rare in clusters due to high speeds of motion. We performed a deep (r-band surface brightness limit of 28 mag/arcsec^2) imaging survey on four rich clusters of galaxies using the CTIO 4m Blanco Telescope and found that a large fraction (40%) of bright member galaxies show strong post-merger features contrary to the theoretical expectation. We performed theoretical calculations on galaxy mergers in cluster environments using semi-analytic approaches and hydrodynamic simulations to understand this. Our calculations confirm that in-situ galaxy mergers are indeed rare in clusters and suggest that many of these post-merger galaxies are instead relics of mergers that happened before they fell into the current cluster. It is critical to consider realistic halo merger histories in the first place to understand galaxy evolution accurately. Physical and realistic modeling of galaxies seems finally possible.
[B2C-4-2] 16:20~16:35
A Suite of Hydrodynamical Simulations for the Lyman-Alpha Forest with Massive Neutrinos
Graziano Rossi (Sejong University, Korea), Nathalie Palanque-Delabrouille, Arnaud Borde, Matteo Viel, Christophe Yeche, James Bolton, James Rich, and Jean-Marc Le Goff
The signature left in quasar spectra by the presence of neutral hydrogen in the Universe allows one to constrain the sum of the neutrino masses with improved sensitivity, with respect to laboratory experiments, and may shed a new light on the neutrino mass hierarchy and on the absolute mass scale of neutrinos. However, this requires a detailed modeling of the line-of-sight power spectrum of the transmitted flux in the Lyman-α (Lyα) forest, which in turns demands the inclusion and careful treatment of cosmological neutrinos. To this end, we present here a suite of state-of-the-art hydrodynamical simulations with cold dark matter, baryons and massive neutrinos, specifically targeted for modeling the low- density regions of the intergalactic medium (IGM) as probed by the Lyα forest at high-redshift. The simulations span volumes ranging from (25 Mpc/h)3 to (100 Mpc/h)3, and are made using either 3×1923 ≃ 21 million or 3×7683 ≃ 1.4 billion particles. The resolution of the various runs can be further enhanced, so that we can reach the equivalent of 3 × 30723 ≃ 87 billion particles in a (100 Mpc/h)3 box size. We adopt a particle-type implementation of massive neutrinos, and consider three degenerate species having masses Mν = 0.1, 0.2, 0.3, 0.4 and 0.8 eV, respectively. We improve on previous studies in several ways, in particular with updated routines for IGM radiative cooling and heating processes, and initial conditions based on second-order Lagrangian perturbation theory (2LPT). This allows us to safely start our runs at relatively low redshift, a fact that reduces the shot noise contamination in the neutrino component and the CPU consumption. Besides providing technical details on the simulations, we present the first analysis of the nonlinear 3D and 1D matter and flux power spectra from these models, and characterize the statistics of the transmitted flux in the Lyα forest including the effect of massive neutrinos. In synergy with recent data from the Baryon Acoustic Spectroscopic Survey (BOSS) and the Planck satellite, and with a grid of corresponding neutrino-less simulations, our realizations will allow us to constrain cosmological parameters and neutrino masses directly from the Lyα forest with improved sensitivity. In addition, our simulations can be useful for a broader variety of cosmological and astrophysical applications, ranging from the three-dimensional modeling of the Lyα forest to
cross-correlations between different probes, the study of the expansion history of the Universe in presence of massive neutrinos, and particle physics related topics. Moreover, while our simulations have been specifically designed to meet the requirements of the BOSS survey, they can also be used for upcoming or future experiments – such as eBOSS and DESI.
[B2C-4-3] 16:35~16:50
UV Properties of Post-merger Galaxies in Rich Abell Clusters at z ≲ 0.1
Yun-Kyeong Sheen (University of Concepción, Chile) and Sukyoung K. Yi
Galaxy clusters are dominated by massive early-type galaxies in the nearby Universe. The massive galaxies in cluster environment are supposed to form at early epoch in a short timescale based on their observational properties and the theoretical galaxy formation scenario. However, we found evidence which demonstrates that a significant fraction of the cluster galaxies have gone through mass-assemblies at recent epoch (z < 0.5) using deep optical images. Actually the fraction of post-merger galaxies in rich Abell clusters was comparable to the fraction of the field ellipticals (38% vs 49% for cluster and field). We interpreted this as a result of continuous halo mergers in the Universe. Some of massive early-type galaxies in galaxy clusters may have carried over their merger features from their previous halo environment (Sheen et al. 2012). All of our cluster samples have very deep GALEX UV images. Taking advantage of the deep UV data, we have investigated recent star formation history of the cluster galaxies and examined a correlation with their post-merger signatures. Furthermore, morphological features of post-merger galaxies and their spatial distribution in cluster halo will be discussed.
[B2C-4-4] 16:50~17:05
Radio Variability and Random Walk Noise Properties of Four Blazars
Jong-Ho Park (Seoul National University, Korea) and Sascha Trippe
The strong and complex temporal flux variability of active galactic nuclei provides valuable information on the internal conditions of accretion zones and plasma outflows. Blazars, characterized by violent flux variability across the entire electromagnetic spectrum, are an extreme subset of AGNs which include BL Lacertae (BL Lac) objects and flat spectrum radio quasars (FSRQs). We present the results of a time series analysis of the long-term light curves of four blazars: 3C 279, 3C 345, 3C 446, and BL Lacertae. We exploit the database of the University of Michigan Radio Astronomy Observatory monitoring program which provides densely sampled light curves spanning 32 years in time in three frequency bands located at 4.8, 8, and 14.5 GHz. Our sources show mostly flat or inverted (spectral indices -0.5 < alpha < 0) spectra, in agreement with optically thick emission. All light curves show strong variability on all timescales. Analyzing the time lags between the light curves from different frequency bands, we find that we can distinguish high-peaking flares and low- peaking flares in accordance with the Valtaoja classification. The periodograms (temporal power spectra) of the observed light curves are consistent with random-walk power-law noise without any indication of (quasi- )periodic variability. Random-walk noise light curves are expected to originate from shocks in discontinuous jets. Our observations provide the first direct test of several theoretical jet models. The fact that all four sources studied are in agreement with being random-walk noise emitters at radio wavelengths suggests that such behavior is a general property of blazars. We are going to generalize our approach by applying our methodology to a much larger blazar sample in the near future.
Poster Session 17:05~17:30 Chairs: Jong-Hak Woo (Seoul National University)
Sascha Trippe (Seoul National University)
Session: [B2C-5] S5 : Compact Objects, High Energy and Particle Astrophysics Date: August 19, 2014 (Tuesday) Time: 16:00~17:25 Room: Room E (Room 107) Chair: Tatehiro Mihara (RIKEN)
[B2C-5-1] 16:00~16:20
[Invited] Neutron Star Structure and Related Astrophysical Problems
Chang-Hwan Lee (Pusan National University, Korea)
Recent observations on 2 solar mass neutron stars in neutron star-white dwarf binaries, PSR J1614-2230 and PSR J0348+0432, have given strong constraints on the maximum mass of neutron stars. On the other hand, all well-measured neutron star masses in double neutron star binaries are still less than 1.5 solar mass. In this talk, I would like to discuss the implications of recent neutron star observations to the neutron star equations of states and the related astrophysical issues. I also would like to discuss the possibilities of super- Eddington accretion during the binary evolution of neutron star progenitors.
[B2C-5-2] 16:20~16:40
[Invited] Multi-Messenger Astronomy of Compact Binaries
Chunglee Kim (Seoul National University, Korea)
Within a decade, gravitational waves (GWs) will provide us with a new probe to explore the Universe and heavenly bodies. GW astronomy will be complimentary to photon- and particle-based astronomy and multi- messenger astronomy can be done with a network of observatories and satellites. Among the predicted GW sources, compact binaries (NS-NS and BH-BH binaries) are one of the most promising ones to be detected on Earth using laser interferometry. Analyzing GW data based on Bayesian Inference will allow us to measure physical parameters of compact binaries, such as masses, location, distance, spin(s), etc. Most interestingly, GWs is a unique tool to study black hole binaries, which are inaccessible by other methods. Focusing on compact binaries, we overview the recent progresses made in the field of GW astronomy. We also discuss strategies and prospects of multi-messenger astronomy in order to study compact objects.
[B2C-5-3] 16:40~16:55
Switching States in Pulsar Magnetosphere
Phrudth Jaroenjittichai (National Astronomical Research Institute of Thailand, Thailand) and Michael Kramer
Switching emission states in intermittent and moding pulsars are suggested to be related via changes in the charge current flows above the polar cap, which are responsible for both radio emission and pulsar‘s spin derivative (or `spin-down'). Because the charge current flows depend on the geometry of the magnetic field lines, the change in the spin-down is predicted to depend on the inclination angle α, measured between the magnetic and spin axes. Using a pulsar's beam model, assuming a dipole geometry, we estimate α of three intermittent pulsars, PSRs B1931+24, J1841+0500 and J1832+0029, and found the results to be consistent with the predictions. Despite the suggested connection between the two phenomena, the changes in the spin- down of moding pulsars can be difficult to measure due to their faster switching timescales. Here, we present a new approach for estimating the variation in the charge current density of moding pulsars, which involves determining the plasma perturbation on the polarisation position angle of each mode. The correlation between the spin-down changes and α can be realised with a sample of moding pulsars using this method, offering another supporting evidence to this picture.
[B2C-5-4] 16:55~17:10
The Electron Fraction and the Fermi Energy of Relativistic Electrons in a Neutron Star
Z. F. Gao (Xinjiang Astronomical Observatory, China) and Q. H. Peng
The electron fraction and the Fermi energy of relativistic electrons in the circumstance of a neutron star (NS) are two important physical parameters influencing directly weak-interaction processes including MURCA reactions, electron capture and so on. This influence will change intrinsic equations of states (EOS), interior structure and heat evolution of a NS, and even affect whole properties of the star. Based on the currently popular and reliable EOSs, we investigate the relationship between the electron fraction and matter density in a wide density range by fitting numerically, and deduce a uniform formula for the Fermi energy of degenerate and relativistic electrons in the weak-magnetic field approximation, from which we can obtain the value of electron Fermi energy given a matter density. By comparing with other classic theoretical models, our methods with the characters of simplification and accuracy can be universally suitable for millisecond and common radio pulsars.
[B2C-5-5] 17:10~17:25
New Relativistic Magnetohydrodynamic Codes Based on Upwind Schemes
Hanbyul Jang (Ulsan National Institute of Science and Technology, Korea) and Dongsu Ryu
High energy astrophysical phenomena are ubiquitous in the universe, i.e. relativistic jets originated from AGNs, accretion disks around black holes, gamma ray bursts, and etc. Relativistic flows are commonly involved and magnetic fields play important roles in these energetic astrophysical events. Therefore building a robust and reliable code for relativistic magnetohydrodynamic (RMHD) is important to correctly interpret the physics of the observed high energy phenomena. Because of complexities in the formulism of RMHD, however, building a code based on upwind schemes has been a challenging project. We present the Jacobian matrix for the RMHD system in laboratory frame which enables to describe the eigenvalues and eigenvectors in considerably simple forms. With the general solutions for quartic equations for the compressible mode, we obtained the full sets of analytic expressions for eigenvalues. We then obtained the analytic forms for the left and right eigenvectors which are well defined in all possible physical states including degenerate ones. Using this newly derived eigen-system for RMHD, we successfully built new RMHD codes based on a total variation diminishing (TVD) scheme and weighted essentially non-oscillatory (WENO) scheme which are second and higher order accurate extensions of upwind schemes, respectively. We compared our codes with HLL-type codes which do not utilize the full eigen-system of RMHD. One dimensional numerical tests demonstrate the performance and robustness of new RMHD.
Session: [B2C-6] S6 : Observing Facilities and International Collaborations Date: August 19, 2014 (Tuesday) Time: 16:00~17:30 Room: Room F (Room 108) Chair: Byeong-Gon Park (Korea Astronomy and Space Science Institute)
[B2C-6-1] 16:00~16:20
[Invited] The Large Binocular Telescope as the first Extremely Large Telescope
Christian Veillet (Large Binocular Telescope Observatory, USA)
Slowly but surely, the Large Binocular Telescope (LBT) is getting closer to his ultimate goals: (1) Offer to its users a very large telescope capable of very efficient observing, thanks to the simultaneous use of pairs of instruments each fed by one of its two 8-4m mirror, (2) allow the incoherent combination of its two beams on a single instrument, bringing the equivalent diameter of the telescope to a stunning 11.7-m, and (3) act as an Extremely Large Telescope (ELT) with a resolution equivalent to a 23-m aperture by coherently combining the light coming from its two mirrors through interferometric observations. We will describe in this talk the current status of the LBT Observatory, including the exquisite performances of its adaptive optics and a couple of exciting results showing that LBT is on its way to be the first of the ELTs. We will also present its short- and mid-term development plan and the opportunities it will offer as training ground and technology demonstrator for the ELTs currently in development.
[B2C-6-2] 16:20~16:40
[Invited] The University of Tokyo Atacama Observatory (TAO) Project
Mamoru Doi (University of Tokyo, Japan)
The University of Tokyo Atacama Observatory (TAO) is a project to construct a 6.5-meter telescope optimized for infrared observations at the summit of Co. Chajnantor, 5,640 m altitude, in northern Chile. Because of high altitude and dry climate, atmospheric windows from 0.9 to 2.5 micron become almost continuous, and new windows at wavelength longer than 25 micron are open. We have operated the 1-m miniTAO telescope since 2009, and have verified superb quality of the site by astronomical observations. We start constructing the 6.5- m telescope since 2013. Overview and present status of TAO project are shown.
[B2C-6-3] 16:40~17:00
Status of the Long Baseline Array
Philip Edwards (CSIRO Astronomy & Space Science, Australia)
Astronomical observations using the Very Long Baseline Interferometry technique in the southern hemisphere are conducted with the Long Baseline Array. The core elements of the LBA are ATNF‘s Parkes 64m telescope, Mopra 22m telescope, and the Australia Telescope Compact Array, and the University of Tasmania‘s Hobart 26m and Ceduna 30m telescopes. On occasions, the Tidbinbilla 70m or 34m telescopes, the Warkworth (New Zealand) 12m telescope, Hartebeesthoek (South Africa) 26m or 15m telescopes, and a single 12m ASKAP dish also participate. The LBA operates in the standard radioastronomy bands between 1.4 and 22 GHz, and, as a three-element array, can operate at 32 GHz. Recent operational constraints on the number of receiver changes at Parkes (a prime focus instrument) have resulted in very few observations at 2.3 or 4.8 GHz in recent years. The LBA operates for 3~4 weeks a year in a 4~5 sessions, with additional out- of-session support for RadioAstron observations and occasional time-critical observations. This talk will further describe the capabilities of the LBA, give examples of recent scientific results from the array, and discuss prospects for the future.
Poster Session 17:00~17:30 Chairs: Byeong-Gon Park (Korea Astronomy and Space Science Institute) Ajit Kembhavi (Inter-University Centre for Astronomy and Astrophysics)
Session: [B3A-1] S1 : Solar System and Sun-Earth Interactions Date: August 20, 2014 (Wednesday) Time: 11:00~12:35 Room: Room A (Room 101~102) Chair: Young-deuk Park (Korea Astronomy and Space Acience Institute)
[B3A-1-1] 11:00~11:20
[Invited] Superflares of Sun-Like Stars
Kazunari Shibata (Kyoto University, Japan)
Using Kepler data, Maehara et al. (2012) have discovered 365 superflares (1034-1036 erg) on 148 solar type stars (G type dwarfs). They revealed that the occurrence frequency of superflares of 1034 erg is once in 800 years, and that of 1035 erg is once in 5000 years on Sun-like stars whose surface temperature and rotation are similar to those of the Sun. It was also found that these superflare stars show quasi-periodic brightness variation, which can be interpreted as a result of rotation of stars with large star spots (Notsu Y. et al. 2013). This interpretation is consistent with standard theory of solar flares and dynamo (Shibata et al. 2013), and has partly been confirmed by spectroscopic observations of some of these stars using Subaru telescope (Notsu S. et al., 2013; Nogami et al. 2014). Furthermore, there were no evidence of hot Jupiters around these superflare stars, suggesting the possibility that superflares may occur on the Sun (Nogami et al. 2014). Shibayama et al. (2013) extended Maehara et al.‘s work to find 1547 superflares on 279 solar type stars from 500 days Kepler data. They basically confirmed the results of Maehara et al., but found that in some Sun-like stars the occurrence rate of superflares was very high, 5 superflares in 500 days (i.e., once in 100 days). We shall discuss what would happen on the civilization and environment of the Earth if such superflares would occur on the Sun.
[B3A-1-2] 11:20~11:40
[Invited] Heating of Solar Active Region
Durgesh Tripathi (Inter-University Centre for Astronomy and Astrophysics, India)
One of the most challenging problems in astrophysics is that of solar coronal heating. Despite of major advancement in observational capabilities as well as theoretical modeling, the solution to this problem remains illusive. Active Region, due to its enhanced heating and brightness, provides excellent target of opportunity to address this problem. The modern solar telescopes have shed new lights towards the understanding of this long-standing problem. Observations suggest that there are different kinds of loop structures present in active regions as well as a significant amount of diffuse emission. Therefore, it is important to study the characteristics of all kind of structures to put good constraints on the theories attempting to explain this problem. Here we review some of the new measurements to study the heating mechanisms in different kind of loop structures and diffuse emission in active regions using the observations recorded by Solar Ultraviolet Measurements of Emitted Radiation (SUMER) onboard SoHO and the Extreme- ultraviolet Imaging Spectrometer (EIS) aboard Hinode. These results show that the properties of warm loops, hot core loops and diffuse emission are consistent with impulsive heating – low frequency nanoflare - scenario. However, the evidences are not strong enough to rule out steady heating completely, in particular for hot core loops. Further measurement using better spectral resolution and temperature coverage is required, which will be provided by Solar-C in near future.
[B3A-1-3] 11:40~12:00
[Invited] Study on the Triggering Mechanism and Predictability of Solar Eruptions
Kanya Kusano (Nagoya University, Japan), Yumi Bamba, Daiko Shiota, Shinsuke Imada, and Shin Toriumi
Solar eruptions, which are observed as solar flares and coronal mass ejections, are the most catastrophic events in our solar system, and the primary cause of severe space weather. Since, however, the triggering mechanism of solar eruptions is still not sufficiently understood, it is crucially important to determine the magnetic field structure characterizing the pre-eruption state both from the scientific point of view and the prediction of solar weather. Here, we study this problem by systematically surveying the nonlinear dynamics caused by a wide variety of magnetic structures in terms of three-dimensional magnetohydrodynamic simulations and the analyses of data provided by the Hinode and the Solar Dynamics Observatory (SDO) satellites. As a result, we found that there are at least two different types of solar eruptions, which are initiated through the different processes called the eruption-induced reconnection and the reconnection-induced eruption. The comparison of simulations and observations suggests that two different configurations of magnetic field on the polarity inversion line favor the onsets of those two types of eruptions, respectively. Both the two configurations consist of the sheared magnetic arcade and the small magnetic bi-polar fields, which are reversed to the potential component or the non-potential component of the sheared magnetic arcade, respectively. These results imply that not only the large-scale sheared magnetic field but also the small-scale magnetic disturbance may determine when and where the solar eruptions can occur. Therefore, we conclude that the sophisticated observation of a solar magnetic field vector is necessary for forecasting solar eruptions. Finally, we will discuss about a new methodology to improve the predictability of onset of solar eruptions based on our study.
[B3A-1-4] 12:00~12:20
[Invited] Spectral Variations of Cosmic Rays
David Ruffolo (Mahidol University, Thailand), Alejandro Sáiz, Pierre-Simon Mangeard, Warit Mitthumsiri, Achara Seripienlert, and Usanee Tortermpun
Galactic cosmic rays at Earth exhibit variations in intensity and spectrum, which are due to solar and heliospheric effects. These include 11-year variations with the solar activity cycle, 22-year variations with the solar magnetic cycle, 27-day variations with solar rotation, and temporary Forbush decreases due to solar storms. Neutron monitors have provided precise information on intensity variations, but precise tracking of spectral variations has proven more challenging. Here we report on work in Thailand, with collaborators in other countries, to observe spectral variations of cosmic rays. In addition to providing information about energetic particle transport in magnetic turbulence, and solar and heliospheric effects, this will allow us to develop a proxy for time-dependent ionization in Earth‘s atmosphere with which to test ideas concerning a connection between solar activity and Earth‘s climate that is mediated by the cosmic ray flux and cloud formation.
[B3A-1-5] 12:20~12:35
Latitude Survey Investigation of Galactic Cosmic Ray Solar Modulation during 1994-2007
Paul Evenson (University of Delaware, USA), Waraporn Nuntiyakul, David Ruffolo, Alejandro Saiz, John Bieber, John Clem, Roger Pyle, Marcus Duldig, and John Humble
The Galactic cosmic ray spectrum exhibits subtle variations over the 22-year solar magnetic cycle in addition to the more dramatic variations over the 11-year sunspot cycle. Neutron monitors are large ground-based detectors that provide accurate measurements of variations in the cosmic ray flux at the top of the atmosphere above the detector. At any given location the magnetic field of the Earth excludes particles below a well-defined rigidity (momentum per unit charge) known as the cutoff rigidity, which can be accurately calculated using detailed models of the geomagnetic field. By carrying a neutron monitor to different locations, e.g., on a ship, the Earth itself serves as a magnet spectrometer. By repeating such latitude surveys with identical equipment a sensitive measurement of changes in the spectrum can be made. In this work, we analyze data from the 1994 through 2007 series of latitude surveys conducted by the Bartol Research Institute, the University of Tasmania, and the Australian Antarctic Division. We show that the curious ―crossover‖ in spectra measured near solar minima during epochs of opposite solar magnetic polarity is related directly to a sudden change in the behavior of solar modulation at the time of the polarity reversal. We suggest that the crossover itself results from the interaction of effects due to gradient/curvature drifts with a systematic change in the interplanetary diffusion coefficient caused by turbulent magnetic helicity.
Session: [B3A-2] S2 : Interstellar Matter, Star Formation and the Milky Way Date: August 20, 2014 (Wednesday) Time: 11:00~12:30 Room: Room B (Room 103) Chair: Toshihiro Handa (Kagoshima University)
[B3A-2-1] 11:00~11:20
[Invited] Near-Infrared Study of Young Galactic Supernova Remnants
Bon-Chul Koo (Seoul National University, Korea)
Young Galactic supernova remnants (SNRs) are where we can observe closely the supernova (SN) ejecta and its interaction with circumstellar/interstellar medium. Therefore, they provide an opportunity to explore the explosion and the final stage of the evolution of massive stars. Near-infrared (NIR) emission lines in SNRs mostly originate from shocked dense material. In shocked SN ejecta, forbidden lines from heavy ions are prominent, while in shocked CSM/ISM, [Fe II] and H2 lines are prominent. [Fe II] lines are strong in both shocked SN ejecta and shocked CSM/ISM, and therefore [Fe II] line images provide a good starting point for the NIR study of SNRs. The number of Galactic SNRs observed in [Fe II] emission lines has increased substantially recently by UKIRT Widefield Infrared Survey for Fe+ (UWIFE), which is an unbiased survey of the Galactic Plane (10º<ℓ<65º; |b| ≤ 1º.5) in [Fe II] 1.644 um line using the UKIRT 4-m telescope. There are now about twenty SNRs detected in [Fe II] lines, some of which have been studied by NIR spectroscopy. In this talk, I will review the NIR observations of SNRs and present recent results on young Galactic core- collapse SNRs.
[B3A-2-2] 11:20~11:40
Supernova Remnants in the Magellanic Clouds
Miroslav D. Filipovic (University of Western Sydney, Australia) and Luke Bozzetto
This is an exciting time for the discovery of supernova remnants (SNRs) in galaxies other than our Milky Way. To date, some 85 SNRs in the MCs are well established with other 20 waiting for confirmation. I will review recent searches for SNRs in the Magellanic Clouds including our present state of knowledge of their comparative properties.
[B3A-2-3] 11:40~12:00
[Invited] Constraints on Supernova Progenitors from Integral Field Spectroscopy of the Explosion Site
H. Kuncarayakti (Universidad de Chile, Chile), G. Aldering, J. P. Anderson, N. Arimoto, M. Doi, L. Galbany, M. Hamuy, Y. Hashiba, K. Maeda, T. Morokuma, and T. Usuda
Despite the large number of observed events, the progenitors of supernovae (SNe) are still not very clearly understood. There have been extensive efforts on both theoretical and observational grounds to constrain the physical properties and evolutionary status of the SN progenitors. A handful of SN progenitors have been directly detected in pre-explosion archival Hubble Space Telescope images, but these detections are very rare and most SNe do not have pre-explosion data available. More observational evidences on SN progenitors are needed to be compared with the theoretical predictions. In this work we attempt to constrain the core-collapse SN progenitor properties based on the study of the SN immediate environment. With this strategy we expect to build a statistical sample without relying on the availability of preexplosion data. The stellar populations present at the SN explosion sites are studied by means of integral field spectroscopy, which enables the acquisition of both spatial and spectral information of the object
simultaneously. The spectrum of the SN parent stellar population gives the estimate of its age and metallicity. With this information, the initial mass and metallicity of the once coeval SN progenitor could be derived. As mass and metallicity are the two most important parameters in stellar evolution, this gives strong constraints on the progenitor stars of each of the SN subclasses. From our initial dataset we have found that SNe Ic are the most massive and metal-rich compared to the other subtypes, and there are indications that binary progenitors are prevalent in producing stripped SNe. While the survey is mostly done in optical, additionally the utilization of near-infrared integral field spectroscopy assisted by adaptive optics enables us to examine the explosion sites in high details. This work is carried out using multiple telescopes equipped with integral field spectrographs in Chile and Hawaii, including VLT and Gemini.
[B3A-2-4] 12:00~12:15
IR-to-X-ray Ratio of Supernova Remnants in the Large Magellanic Cloud
Ji Yeon Seok (Academia Sinica Institute of Astronomy and Astrophysics, Taiwan), Bon-Chul Koo, and Hiroyuki Hirashita
Infrared-to-X-ray flux ratio (IRX) traces the relative importance of dust cooling to gas cooling in astrophysical plasma. Dust grains are predicted to be a dominant coolant in the lifetime of a supernova remnant (SNR). We derive IRXs of SNRs in the Large Magellanic Cloud (LMC) using Spitzer and Chandra SNR survey data. We find that the IRXs of all the SNRs in our sample are moderately greater than unity, indicating that dust is more efficient coolant than gas although gas cooling is not negligible. Comparison to IRXs of Galactic SNRs shows that the IRXs of the LMC SNRs are systematically lower than those of the Galactic SNRs. As both dust cooling and gas cooling are pertaining to properties of the interstellar medium, the lower IRXs of the LMC SNRs may reflect the characteristics of the LMC, and the lower dust-to-gas ratio of the LMC (one-forth of the Galactic value) is likely to be the most significant. The observed IRXs are compared to theoretical predictions, which prove to overproduce the observed IRXs by an order of magnitude. This may originate from the dearth of dust in the remnants either due to severe dust destruction via sputtering or due to the local variation of the dust abundance in the preshock medium as compared to the global dust abundance. Finally, we discuss implications for the dominant cooling mechanism in low metallicity galaxies.
[B3A-2-5] 12:15~12:30
Star Formation in Extreme Galactic Environments
Quang Nguyen Luong (Canadian Institute for Theoretical Astrophysics, Canada), Frederique Motte, Fabian Louvet, and Tracey Hill
Recently, observations of star formation has been revolutionized by the availability of observation platforms across the infrared to mm wavelengths. It has enabled us characterizing the star formation activities from the scales of individual protostars (0.1 pc) in the Galactic environments to the scales of molecular cloud complexes (100 pc MCCs) at distant extragalactic environments. MCCs are on one hand the building blocks of star-forming galaxies and on the other hands are the hosting sites of massive star formation. By combining large scales dust continuum surveys mainly from Herschel, Spitzer with molecular line surveys from ground-based telescopes, we have resolved the structures, physical properties and star formation activities of the MCC in the Galaxy down to a great spatial and spectral resolutions. We are able now to investigate the dependency of star formation rates of MCCs on its mass and and density. It turns out that star formation in the Galaxy are occurring mostly occurring in a few MCCs which are located at some extreme dynamical environments such as Bar-Arm junctions and other highly dynamical regions. There are a few clues that the strong dynamics of these places are responsible for the starbursts events in the Galaxy which make us term them as ministarburst. The ministarbursts turn out to be dominant structures of high-z starbursts. We suggest that the differences in star formation rates between starburst vs normal galaxies or between ministarburst vs normal molecular cloud complexes are created by two different modes of star formation.
Session: [B3A-3] S3 : Stars, Exoplanets and Stellar Systems Date: August 20, 2014 (Wednesday) Time: 11:00~12:30 Room: Room C (Room 104) Chair: Se-Hyung Cho (Korea Astronomy and Space Science Institute)
[B3A-3-1] 11:00~11:15
Photometric Study of The Magnetic Cataclysmic Variable RXSJ1803
Young Hee Kim (Chungbuk National University, Korea), Joh-Na Yoon, Yonggi Kim, and Ivan L. Andronov
The University Observatory of Chungbuk National University are monitoring some magnetic cataclysmic variables with 1m telescope at Mt. Lemmon, 1.8m telescope at Mt. Bohyun, and 0.6m telescope at the Jincheon station, former 2 telescopes of which belong to KASI(Korea Astronomy and Space Institute). The time series data of RXSJ1803 from the program stars are reduced and analysed and some results will be presented in this paper. The VR photometric data from 2010 to 2013 are used for RXSJ1803. In additiion to results from the photomtric studies, we also present results of the newly discovered W-UMa type eclipsing binary VSX J180243.9+400331 in the field of RXSJ1803. This star shows a nearly identical depths of the primary and secondary minima. We tried to find the statistically optimal degree of the trigonometric polynomial and the ephemeries in compared with the results by Andronov et al. (2012). Figure 1. shows the light curve of this star with the period of 0.3348837±0.0000002 day. The statistically optimal phenomenological modeling has been carried out with the NAV(New Algol Variable) algorithm and the corresponding parameters have been determined in this paper.
[B3A-3-2] 11:15~11:30
Mid-Infrared Period-Metallicity-Luminosity Relations and Kinematics of RR Lyrae Variables
A. K. Dambis (Sternberg Astronomical Institute, Russia), L. N. Berdnikov, A. Y. Kniazev, V. V. Kravtsov, A. S. Rastorguev, R. Sefako, O. V. Vozyakova, and M. V. Zabolotskikh
We use ALLWISE data release W1- and W2-band epoch photometry collected by Wide-Field Infrared Survey Explorer (WISE) to determine the slopes of the period-luminosity relations for RR Lyrae stars in 15 globular clusters in the corresponding bands. We further combine these results with V- and K-band photometry of Galactic field RR Lyrae stars to determine the metallicity slopes of the log PF - [Fe/H]-MK, log PF - [Fe/H]-MW1, and log PF - [Fe/H]-MW2 period-metallicity-luminosity relations. We infer the zero points of these relations and determine the kinematical parameters of thick-disk and halo RR Lyraes via statistical parallax, and estimate the RR Lyrae-based distances to 19 Local-Group galaxies.
[B3A-3-3] 11:30~11:45
V5584 Sgr: A Moderately Fast Nova of Fe II Class with CO Bands in Emission
Ashish Raj (Korea Astronomy and Space Science Institute, Korea), N. M. Ashok, D. P. K. Banerjee, and Sang Chul Kim
The near-infrared spectroscopic and photometric observations of nova V5584 Sgr will be presented. The observations were taken during the first 12 days following its discovery on 2009 October 26.439 UT. It is clearly evident from the JHK spectra of the nova that the nova belongs to the Fe II class. The spectra show first-overtone CO bands in emission between 2.29-2.40 µm together with H I, C I, N I and O I emission lines. The H I, Pa β and Br γ spectral lines show deep P Cygni profiles having FWHM of 550-650 km s−1. The distance for the nova have been estimated as d = 6.3 ± 0.5 kpc using the MMRD relation and with an estimated value of t2 = 25 ± 1 days from the optical light curve. The observed t2 value places V5584 Sgr in the class of moderately fast novae. Using WISE and other publicly available data, we found that the nova
underwent a pronounced dust formation phase during February - April 2010. We have also estimated the range for the upper limit of the CO mass for V5584 Sgr.
[B3A-3-4] 11:45~12:00
Existence of Non-planar Triangular Equilibrium Points in Elliptic Restricted Three-Body Problem under the Effects of Radiation and Oblateness
Budi Dermawan (Bandung Institute of Technology, Indonesia), I. N. Huda, R. W. Wibowo, T. Hidayat, J. A. Utama, D. Mandey, and I. Tampubolon
This work considers the elliptic restricted three-body problem with non point-mass primaries. We include effects of radiation of the bigger primary and an oblate smaller primary to mimic an exoplanetary system with a gas giant planet. Under the influences of both effects we look for the existence of the triangular equilibrium points. We set the system in a normalized rotating coordinate system and derive equations of motion of the third infinitesimal object. Our study shows that the triangular equilibrium points are existent such as in classical case of point-mass primaries. Both effects dislocate the triangular equilibrium points and modify their equilateral/isosceles triangle shape with respect to the primaries. The oblateness also induces vertical region about the triangular equilibrium points and this causes the points can exist in non-planar. This result suggests that, if stable, an infinitesimal object may reside in the triangular region away from the exoplanet‘s orbital plane.
[B3A-3-5] 12:00~12:15
Hidden Secrets in Stellar Loci: Metallicity Dependences, Intrinsic Widths and Binaries
Haibo Yuan (Peking University, China), Xiaowei Liu, Maosheng Xiang, Yang Huang, and Bingqiu Chen
Stellar loci are widely used in selecting interesting outliers, reddening determinations and calibrations, recently. However, hitherto no dependence of stellar loci on metallicity has been considered and their intrinsic widths are unclear. Yuan et al. (2014a, to be submitted) have re-calibrated the SDSS stripe 82 imaging data using a spectroscopy based Stellar Color Regression (SCR) method and achieved an unprecedented accuracy of 5, 3, 2 and 2 mmag in the u-g, g-r, r-i and i-z colors, respectively. By combining the re-calibrated imaging and spectroscopic data in the stripe 82, we have built a large, clean sample of dwarf stars with extremely accurate colors and well determined metallicities. In the first part of this talk, we investigate the metallicity dependence and intrinsic widths of the SDSS color loci (Yuan et al. 2014b, to be submitted). Typically, one dex decrease in metallicity causes 0.20 and 0.02 mag decrease in u-g and g-r colors, and 0.02 and 0.02 mag increase in r-i and i-z colors, respectively. The variations are larger for metal-rich stars than for metal-poor ones and for F/G/K stars than for A/M stars. Using the sample, we have performed two dimensional polynomial fitting to the u-g, g-r, r-i and i-z colors as a function of the g-i color and metallicity. The residuals, at the level of 0.029, 0.008, 0.008 and 0.011 mag respectively for the u-g, g-r, r-i and i-z colors, can be fully accounted by the photometric errors and metallicity uncertainties, suggesting that the intrinsic widths of the loci are at maximum of a few mmag if not zero. The residual distributions are asymmetric, revealing that a significant fraction of stars are binaries. Binaries play a key role in understanding star formation and evolution. Previous techniques in searching for binaries are biased to close (or wide) binaries of similar masses and limited to the solar neighborhood. In the second part of this talk, we propose a Stellar Locus OuTlier (SLOT) method and apply it to the stripe 82 to determine binary fraction for field FGK stars (Yuan et al. 2014c, to be submitted). The method is insensitive to neither the orbital period nor the mass-ratio distributions. With modern photometric and spectroscopic surveys, it will provide an unbiased estimate of binary fraction for a large sample of stars. It can also constrain mass ratio distribution when applying the method to star clusters, and orbital period distribution when applying to stars of repeated spectroscopic observations. We have applied the SLOT method to the re-calibrated stripe82 imaging data using spectroscopic data from both the SDSS and LAMOST. We find that the average binary fraction for field FGK stars are 41±2%, and the fraction decreases toward later spectral types. The binary fractions for the Galactic thin, thick disk stars are very close. However, there is some indication that the halo contains a larger fraction of binary stars contrary to expected. In the end, other implications of the metallicity dependent stellar loci and future work with the SLOT method are discussed.
[B3A-3-6] 12:15~12:30
Search for Stellar Substructures of Four Metal-Poor Globular Clusters in the Galactic Bulge Region
Sang-Hyun Chun (Yonsei University, Korea), Minhee Kang, DooSeok Jung, and Young-Jong Sohn
We present the stellar density distribution around four metal-poor globular clusters (NGC 6266, NGC 6626, NGC 6642, and NGC 6723) in the Galactic bulge region. Based on near-infrared JHK observations obtained with WFCAM detector on United Kingdom Infrared Telescope, we secured homogeneous and wide-field photometric images in the vicinity of the clusters. In order to reduce the field star contamination and trace cluster member stars, a statistical weighted filtering method was applied on the color-magnitude diagram. Two-dimensional isodensity contour maps of clusters indicate that all four globular clusters show strong evidence of tidally stripping stellar features beyond the tidal radius in the form of a tidal tail or small density lobes/chunk. The extending stellar substructures are likely associated with the effect of the dynamical interaction with the Galaxy and the cluster‘s space motion. The radial density profiles of clusters accurately describe observed stellar substructures as overdensity features. These overdensity features have a break in slope and depart from the theoretical King and Wilson models at the outer region of the clusters. These observed results imply that four globular clusters in the Galactic bulge region experienced a strong environmental effect, such as tidal force or bulge/disk shock of the Galaxy in the dynamical evolution of the globular clusters. These observational results provide us further constraints for understanding the evolution of clusters in the Galactic bulge region as well as the mass assembly history of the Galaxy.
Session: [B3A-4] S4 : Galaxies, AGN and Cosmology Date: August 20, 2014 (Wednesday) Time: 11:00~12:30 Room: Room D (Room 105~106) Chair: Nguyen Quynh Lan (Hanoi National University of Education)
[B3A-4-1] 11:00~11:20
[Invited] Constraints on Pre-Inflation Cosmology and Dark Flow
G. J. Mathews (University of Notre Dame, USA), N. Q. Lan, and T. Kajino
This talk summarizes current constraints on cosmic dark flow and prospects for observing the pre-inflation -Collaboration and WMAP 9-yr analysis. If the present universe is slightly open then preinflation curvature will appear as a cosmic dark-flow component of the CMB dipole moment. We summarize current cosmological constraints on this cosmic dark flow and analyze the possible constraints on parameters characterizing the pre-inflating universe in an inflation model with a present- We employ an analytic model to show that for a broad class of inflation-generating effective potentials, the simple requirement that the observed dipole moment represents the pre-inflation curvature as it enters the horizon, allows one to set upper and lower limits on the magnitude and wavelength scale of pre-inflation fluctuations in the inflaton field and the curvature of the pre-inflation universe, as a function of the fraction of the total initial energy density in the inflaton field. We estimate that if the current CMB dipole is a universal dark flow (or if it is near the upper limit set by the Planck Collaboration) then the present -inflating universe for a broad range of the fraction of the total energy in the inflaton field at the onset of inflation. Such small pre-inflation curvature might be indicative of open-inflation models in which there are two epochs of inflation
[B3A-4-2] 11:20~11:40
[Invited] 21cm Cosmology
Tzu-Ching Chang (Academia Sinica Institute of Astronomy and Astrophysics, Taiwan)
*To be announced
[B3A-4-3] 11:40~12:00
[Invited] Probing Galaxy Formation Models in Cosmological Simulations with Observations of Galaxy Groups
Habib Khosroshahi (Institute for Research in Fundamental Science, Iran), Ghassem Gozaliasl, Alexis Finoguenov, Mojtaba Raouf, and Halime MirAghee
Majority of galaxies reside in groups and clusters where they are understood to evolve through galaxy-galaxy interactions. Galaxy groups and clusters are also hosts to some of the most massive galaxies observed in the Universe. Multiple mergers of galaxies in the core of galaxy group can produce such massive galaxies and develop a large luminosity gap or luminosity deficiency, at the vicinity of the formed giant galaxy. This luminosity gap, carries information that allows us to probe the galaxy formation/evolution models in combination with other observables. Employing a wide range of observations from X-ray to radio through optical, combined with the cosmological simulations, we present and discuss the capabilities that the luminosity gap offers to constraint galaxy formation models in the local and the distant universe. Using the Millennium simulations, we introduce an age-dating routine for galaxy groups and clusters, based
on optically measurable properties of galaxies from photometric and spectroscopic observations. By defining the ―age‖ of galaxy groups and clusters based on the halo mass accumulation we are able to identify a sub- region in the parameter space of, group stellar mass, luminosity of the brightest group galaxy (BGG), the luminosity gap and the physical separation of the BGG and the luminosity centroid, which statistically results in ―old‖ galaxy group halos, e.g. the groups which have acquired over 50 per cent of their present day mass at z=1. Such a sample of galaxy groups with an age indicator is invaluable for connecting the observed properties of galaxies to the halo formation history or age. Using a large sample of galaxy groups observed by the XMM-Newton X-ray telescope observations as part of the XMM-Large Scale Survey, we carried out a statistical study of the redshift evolution of the luminosity gap for a well defined mass-selected group sample and show the relative success of some of the semi-analytic models in reproducing the observed properties of galaxy groups up to redshift z~1.2. The observed trend argues in favour of a stronger evolution of the feedback from active galactic nuclei at z<1 compared to the models. The slope of the relation between the magnitude of the brightest cluster galaxy and the value of the luminosity gap does not evolve with redshift and is well reproduced by the models, indicating that the tidal galaxy stripping, put forward as an explanation of the occurrence of the magnitude gap, is both a dominant mechanism and is sufficiently well modelled. We provide observational evidences that the ongoing and the old AGN activities, probed by 1.4 GHz and 610 MHz radio observations, using the GMRT, is linked to the presence of the large luminosity gap, such that giant elliptical galaxies residing in groups with a large luminosity gap (> 2 mag) are dimmer in the radio luminosity, relative to the giant elliptical galaxies with the same optical luminosity but in groups with smaller luminosity gap. These findings offer additional constraints for galaxy formation models when observables such as the radio luminosity becomes available in the future developments of these models.
[B3A-4-4] 12:00~12:15
Revisiting WMAP Beam Profiles via Planck Radio and SZ Catalogues
U. Sawangwit (National Astronomical Research Institute of Thailand, Thailand), J. R. Whitbourn, and T. Shanks
The prime evidence underpinning the standard ΛCDM cosmological model is the CMB power spectrum as observed by WMAP and other microwave experiments. But Sawangwit & Shanks (2010) have shown that the WMAP CMB power spectrum is highly sensitive to the beam profile of the WMAP telescope. Here, we use the source catalogue from the Planck Early Data Release to test further the WMAP beam profiles. We confirm that stacked beam profiles at Q, V and particularly at W appear wider than expected when compared to the Jupiter beam. The same result is also found based on WMAP-CMBfree source catalogues and NVSS sources. The accuracy of our beam profile measurements is supported by analysis of CMB sky simulations. However, the beam profiles from WMAP7 at the W band are narrower than previously found in WMAP5 data and the rejection of the WMAP beam is now only at the ≈3σ level. We also find that the WMAP source fluxes demonstrate possible non-linearity with Planck fluxes. But including ground-based and Planck data for the bright sources may suggest that the discrepancy is a linear offset rather than a non-linearity. Additionally, we find that the stacked Sunyaev-Zel‘dovich (SZ) decrements of ≈ 151 galaxy clusters observed by Planck are in agreement with the WMAP data. We find that there is no evidence for a WMAP SZ deficit as has previously been reported. In the particular case of Coma we find evidence for the presence of an O(0.1mK) downwards CMB fluctuation. We conclude that beam profile systematics can have significant effects on both the amplitude and position of the acoustic peaks, with potentially important implications for cosmology parameter fitting.
[B3A-4-5] 12:15~12:30
The Taipan Survey: Cosmology from the Nearby Universe
Matthew Colless (Australian National University, Australia)
One of the most fundamental tasks in astronomy is to determine the cosmological model describing the physics of the expanding Universe in terms of its matter-energy content and the laws of gravity. Recent observations of the Universe show that our current understanding of the relevant physics is profoundly incomplete, forcing cosmologists to invoke a dark energy that propels acceleration in the present-day expansion of the Universe and affects the growth rate of large-scale structures and the motions of galaxies. The Taipan survey will measure redshifts for 500,000 galaxies and peculiar velocities for a subset of 50,000
early-type galaxies over the whole southern sky. It will use a refurbished UK Schmidt Telescope at Siding Spring Observatory together with an innovative ‗starbugs‘ optical-fibre positioner and a purpose-built spectrograph. The survey will yield the best direct measurement of the present-day expansion rate of the Universe, the largest maps of the density and velocity fields of local structures, and unique new tests of large- scale gravitational physics using galaxy motions, including tests of modified theories of gravity. It will also provide a legacy database for synergy science programs. The Taipan survey's new map of the Universe will significantly improve current understanding of three fundamental questions about the standard cosmological model: 1. What is the expansion rate of the Universe? The survey will yield a 1% measurement of Hubble's constant, H0, from the baryon acoustic oscillation signature in the large-scale distribution of galaxies. This will be the most precise and direct measurement of H0, and will yield improved measurements of several other fundamental parameters of the cosmological model. 2. What are the density and velocity fields in the local universe? The survey will produce detailed maps of the density and the velocity fields over a much larger volume than all previous surveys. The statistical properties and consistency of these fields provide key tests of the standard cosmological model, and independent measurements of key parameters not accessible from redshift surveys alone. 3. What is the growth rate of structure? The survey will make a stringent test of whether General Relativity is the correct theory of gravity for scales up to a billion light-years, based on two independent and complementary methods for measuring the growth rate of structure from galaxy velocities. Any deviations from the predictions of General Relativity would provide vital clues to modifying the theory of gravity. Here I will present the overall survey strategy, describe the instrumentation being developed for survey observations, and provide forecasts for the results of the survey based on detailed simulations. The Taipan survey is expected to commence observations in early 2016 and to be completed by 2020.
Session: [B3A-5] S5 : Compact Objects, High Energy and Particle Astrophysics Date: August 20, 2014 (Wednesday) Time: 11:00~12:20 Room: Room E (Room 107) Chair: Hyesung Kang (Pusan National University)
[B3A-5-1] 11:00~11:20
[Invited] The TeV Gamma-Ray Milky Way
Gavin Rowell (University of Adelaide, Australia)
TeV (1012 eV) gamma-rays provide crucial information about extreme environments in the Universe. In our Millky Way, about 70 TeV gamma-rays sources are now known., which are linked to objects such as supernova-remnants, pulsars, pulsar-powered nebulae, compact binary systems, molecular clouds, and perhaps, massive stellar clusters. Over 30% of the Galactic TeV sources however, remain unidentified. The TeV gamma-ray emission allows crucial insights into the types of particles being acceleration and how they interact with their environment. In this talk I will present a status report on the field, highlight recent advances, and, outline the intimate links that Galactic TeV gamma-ray astronomy has with surveys of the interstellar medium. I will conclude with a look at the future of TeV gamma-ray astronomy via next generation facilities such as CTA.
[B3A-5-2] 11:20~11:35
Fast-Cooling Synchrotron Radiation in a Decaying Magnetic Field and Gamma-Ray Burst Emission Eechanism
Z. Lucas Uhm (Peking University, China) and Bing Zhang
Synchrotron radiation of relativistic electrons is an important radiation mechanism in many astrophysical sources. In the sources where the synchrotron cooling timescale is shorter than the dynamical timescale, electrons are cooled down below the minimum injection energy. It has been believed that such ‗fast cooling‘ electrons have a power-law distribution in energy with an index -2, and their synchrotron radiation has a photon spectral index -1.5. On the other hand, in a transient expanding astrophysical source, such as a gamma-ray burst (GRB), the magnetic field strength in the emission region continuously decreases with radius. Here we study such a system, and find that in a certain parameter regime, the fast-cooling electrons can have a harder energy spectrum. We apply this new physical regime to GRBs, and suggest that the GRB prompt emission spectra whose low-energy photon spectral index has a typical value -1 could be due to synchrotron radiation in this moderately fast-cooling regime. For details, see Uhm & Zhang 2014, Nature Physics, 10, 351.
[B3A-5-3] 11:35~11:50
Frequency Independent Quenching of Pulsed Emission
Vishal Gajjar (National Centre for Radio Astrophysics, India), Bhal Chandra Joshi, Michael Kramer, Ramesh Kurrupswamy, and Roy Smits
Pulsars show a variety of pulse to pulse variation in their pulsed emission. The most dramatic variation seen in many pulsars, with emission in a burst of one to several pulses interspersed with pulses with no detectable radio emission, is called pulse-nulling. This phenomenon has been reported in more than 100 pulsars to date. There are two different group of theories that attempt to explain the cause of nulling. Intrinsic effects such as cessation of primary particles on short time-scale, loss of coherence conditions or changes in the current flow may cause a pulsar to null. However, geometric effects such as line-of-sight passing between the emitting sub-beams or changes in the direction of the entire emission beam can also mimic absence of detectable
emission. As the emission at various radio frequencies originate at distinct heights from the neutron star surface, the spacing between the sub-beam, in the rotating carousal, may also differ significantly from lower to higher frequencies. Thus, the empty line-of-sight hypothesis, also known as the pseudo-nulls, be tested with simultaneous multiple frequency observations. There are very few long simultaneous observations of nulling pulsars reported so far. In this study, the simultaneous occurrence of the nulling phenomena in three pulsars, PSRs B0031-07, B0809+74 and B2319+60, was investigated. The observations were conducted simultaneously at four differ ent frequencies, 313, 607, 1380 and 4850 MHz, from three different telescopes viz. the GMRT, the WSRT and the Effelsberg radio telescope. We obtained the nulling fraction at each frequency which were found to be consistence within the error bars, at all four frequencies for all three pulsars. Similarly, the single pulse emission states were also compared using the contingency table analysis. To measure the stastical significance of the contingency tables, we measured the Cramer-V and the uncertainty coefficient for each pair of frequencies. For all three pulsars, both the statistical tests showed highly significant broadband nulling behaviour. About 44 out of 6776 pulses do not show simultaneous null (burst) state for PSR B0031-07. Among these, 25 occurred either at the start or at the end of a burst. There were 27 and 158 pulses observed in PSRs B0809+74 and B2319+60, respectively, where the emission states were not identical across the frequencies. Similar to PSR B0031-07, 20 and 82 of these occurred at the start/end of a burst for PSRs B0809+74 and B2319+60, respectively. Thus, while the nulling patterns for the three pulsars is largely broadband, deviations from this behaviour is seen in about one percent of pulses, about half of which occur at the transition from null to burst (or vice-verse). These results clearly suggest that nulling is truly a broadband phenomena and favors models invoking magnetospheric changes on a global scale compared to local geometric effects as a likely cause of nulling in these pulsars.
[B3A-5-4] 11:50~12:05
Broadband Turbulent Spectra in Gamma-ray Burst Light Curves
Maurice H. P. M. van Putten (Sejong University, Korea), Cristiano Guidorzi, and Filippo Frontera
Broadband power density spectra offer a window to understanding turbulent behavior in the emission mechanism and, at the highest frequencies, in the putative inner engines powering long gamma-ray bursts (GRBs). We recently introduced a chirp search method alongside Fourier analysis for signal detection in the Poisson noise-dominated, 2 kHz sampled, BeppoSAX light curves (2014, ApJ, 786, 146). Using an efficient numerical implementation in O (Nn log n) operations, where N is the number of chirp templates and n is the number of samples in the data time series, we show a continuation of the spectral slope of Fourier-chirp spectra of GRB 010408 and GRB 970816 up to 1 kHz of Kolmogorov turbulence. The same continuation is observed in an average spectrum of 42 bright, long GRBs. In light of the recently funded KAGRA gravitational wave detector in Japan, we include an outlook on a similar analysis of upcoming gravitational wave data in searches for nearby GRBs and core-collapse supernovae.
[B3C-5-5] 12:05~12:20
Thermal Stability of a Thin Disk with Magnetically Driven Winds
Shuangliang Li (Shanghai Astronomical Observatory, China) and Mitchell Begelman
The absence of thermal instability in the high/soft state of black hole X-ray binaries, in disagreement with the standard thin disk theory, has been a long-standing riddle for theoretical astronomers. We have tried to resolve this question by studying the thermal stability of a thin disk with magnetically driven winds in the M_dot- Σ plane. It is found that disk winds can greatly decrease the disk temperature and thus help the disk become more stable at a given accretion rate. The critical accretion rate, M_dot_ crit, corresponding to the thermal instability threshold, is significantly increased in the presence of disk winds. For α = 0.01 and Bφ = 10Bp, the disk is quite stable even for a very weak initial poloidal magnetic field [βp,0 ∼ 2000, βp = (Pgas + Prad)/(B2 p /8π)]. However, when Bφ = Bp or Bφ = 0.1Bp, a somewhat stronger (but still weak) field (βp,0 ∼ 200 or βp,0 ∼ 20) is required to make the disk stable. Nevertheless, despite the great increase of M_dot_ crit, the luminosity threshold, corresponding to instability, remains almost constant or decreases slowly with increasing M_dot_ crit due to decreased gas temperature. The advection and diffusion timescales of the large-scale magnetic field threading the disk are also investigated in this work. We find that the advection timescale can be smaller than the diffusion timescale in a disk with winds, because the disk winds take away most of the gravitational energy released in the disk, resulting in the decrease of the magnetic diffusivity η and the increase of the diffusion timescale.
Session: [B3A-6] S6 : Observing Facilities and International Collaborations Date: August 20, 2014 (Wednesday) Time: 11:00~12:30 Room: Room F (Room 108) Chair: Michael Burton (University of New South Wales)
[B3A-6-1] 11:00~11:20
[Invited] Paper Title Chinese Antarctic Observatory at Dome A
Ji Yang (Purple Mountain Observatory, Chinese Academy of Sciences, China)
The exceptionally good observing conditions at Dome A have attracted extensive attention to astronomical community. After the successful traverse to Dome A, site surveys have been conducted at Dome A and demonstrated its excellent observing conditions for ground-based astronomy from optical to THz. A brief review will be made on the results from the site surveys. Small- to mid-size instruments have been used at Dome A for continuing site survey and astronomical observations through the solid supports from Polar Research Institute. A number of discoveries have been achieved by these instruments. Dome A has been selected as one of the goals of development for Chinese astronomy for the next decade. Major Instruments, including a 2.5m opt/NIR telescope and a 5m THz telescope, are proposed as National Mega-Science Facility. Conceptual designs have been carried out during the past two years. Significant progress has been achieved in R&D for the two telescopes and some details on the THz telescope will be explained.
[B3A-6-2] 11:20~11:40
[Invited] Astronomy at Dome Fuji in Antarctica
Takashi Ichikawa (Tohoku University, Japan)
Antarctica is the last window open to space for ground-based astronomical observations. The highest peaks of the Antarctic plateau above 3,000 m elevation are expected to be the best places for observational astronomy. Due to low temperature, thermal noise at infra-red wavelengths is much lower in Antarctica than other temperate sites. Dry atmosphere with extremely low water vapor is much more transparent in infra-red to sub-millimeter. The wind is weak and stable. No violent storms and blizzards come. Since the surface inversion layer is thin, we can expect good seeing. To enjoy such advantages in inland Antarctica and to promote the astronomy at one of highest peaks, Dome Fuji (3810m height), Japanese group has organized a consortium consisting of universities and institutes. The activities for astronomy at Dome Fuji station of National Institute of Polar Research Japan were started in 2010. During the six-year program, the instruments and facilities for the site testing have been deployed in 2011 and 2013. For that purpose, PLATO-F, which is a self-contained automated platform for conducting year-round experiments completely robotically from the Antarctic plateau, was constructed under the collaboration with UNSW. The result of the seeing measurement with Tohoku-DIMM was published in Okita et al. (2013), in which the best seeing 0.2" at optical wavelength was reported. The study of the atmospheric turbulence shows the boundary layer profiles (Okita et al. in preparation), which would be very helpful for future adaptive-optics applications. Near-infrared and THz telescopes, which are now under budget request, will be main facilities for astronomy. Thanks to low background and high transmittance, a 2m-class telescope has a capability of 8m-class telescopes located at Mounakea in near-/mid-infrared. An infrared survey observation in K-dark band at 2.4 micron will give the deepest and widest dataset for the high-z universe with reasonable cost and observation time. It will reach deeper than those of VISTA and UKIDSS by 1-2 mag. The THz telescope will target dusty galaxies at the high-z universe to study galaxy evolution in its early phase of star formation enshrouded in dust. The long polar night in winter is favorable for searching variable objects with a long period such like extra-solar planets
in orbit of habitable zone. The observation with molecules (e.g., CO, H2O, CH4) at the second eclipse will give us the information of the atmosphere.
[B3A-6-3] 11:40~11:55
HEAT @ Ridge A – the High Elevation Antarctic Terahertz Telescope
Michael Burton (University of New South Wales, Australia), Catherine Braiding, Michael Ashley, and John Storey
HEAT is a 62cm THz frequency telescope operating at the driest location known on the Earth‘s surface – the 4,000m elevation Ridge A near to the summit of the Antarctic plateau at Dome A. Here the atmospheric precipitable water vapour content is virtually always no more than 250µm ppt H2O, and falls to below 100µm at times in the middle of winter, so opening the THz windows to ground-based observations. In particular, this permits measurement of key diagnostic spectral emission lines arising from the transition from diffuse-to- dense gas clouds in the interstellar medium – i.e. of [CI], [CII] and [NII]. HEAT was built by the University of Arizona and is now in its third season of operations at Ridge A. It is a robotic facility, controlled by the PLATO autonomous laboratory built by the University of New South Wales, one of 4 such modules now operating on the Antarctic plateau. Its installation, via a remote field deployment, represents a new way of conducting frontline science in Antarctica at low cost. HEAT runs off just 150W of power, with closed-cycle coolers bringing the detectors to 50K. A tiltable mirror is used to direct the beam into a fixed, off-axis instrument, making use of Earth rotation to provide imaging capability through drift scanning. A mapping survey of the Galactic plane is now underway in the [CI] 0.8 THz line, providing ~2 arcminute and 1 km/s resolution. A [NII] 1.5 THz mapping survey is about to begin. For further information, please see the project website at http://soral.as.arizona.edu/heat/.
Poster Session 11:55~12:30 Chair: Michael Burton (University of New South Wales)
Session: [B3B-1] S1 : Solar System and Sun-Earth Interactions Date: August 20, 2014 (Wednesday) Time: 14:00~15:25 Room: Room A (Room 101~102) Chair: Kyungsuk Cho (Korea Astronomy and Space Science Institute)
[B3B-1-1] 14:00~14:20
[Invited] Solar and Space Weather Studies in Korea
Y. -D. Park (Korea Astronomy and Space Science Institute, Korea), K. S. Cho, and J.-J. Lee
We introduce Korean solar physics and space weather research. In spite of short history, we have been developed very fast in these research fields. For the solar physics researches, we take the best data from NST what is the largest ground base solar telescope in BBSO of USA as well as the best high resolution space based solar image from the SDO by the co-operation with NJIT and NASA. Particularly, FISS which is installed on 2009 at the NST in BBSO get very high resolution spectroscopic images and derive excellent research papers. In the field of space weather forecast and research, RRA become the membership of International Space Environment Service Network as on behalf of Korean space weather and KMA and KASI are constructed many space weather infrastructures. As one of infra structure, KASI constructed the RBSP receiving system for the space weather research. RBSP is observe the radiation belt with two satellites which were launched August 30, 2012 by NASA. Also, RRA and KMA developed space weather monitoring system as well as many Universities and KASI developed space weather forecast model to increase the space weather forecast probabilities.
[B3B-1-2] 14:20~14:35
Relationship of Smoothed Sunspot Number and Land Surface Temperature In the Philippines
John Christian B. Lequiron (Rizal Technological University, Philippines)
The study have presented the archived data of existing Land Surface Temperature (LST) and Smoothed Sunspot Number (SSN) on local (PAGASA) and international (NOAA) institutions with the purpose of determining the effect of the different climate types of the Philippines to the relationship of SSN and LST. The researcher used the descriptive method in this study, to assess the relationship of SSN and LST in the Philippines. This method enabled the researcher to identify and conclude if such relationship exists in the two variables. The findings of the study are the following; there is a negligible correlation between the relationship of SSN and LST in most of the stations having different climate types but Laoag, Ilocos Region and the stations in Climate Type IV have a higher correlation value than the other stations. Even though that stations having a climate type IV has a negligible correlation between the SSN and LST, it is still significantly different from the other climate types because it has the highest correlation values due to its dry season throughout the year. With the above findings, the researcher concluded that; there is no existing relationship between SSN and LST in the Philippines but there are stations that has a correlation between the SSN and LST due to the existence of dry season. Regions having a dry season throughout the year tend to have higher correlations than those having a wet season throughout the year. Lastly, there are other factors other than rainfall that affects the relationship of SSN and LST in a certain region.
[B3B-1-3] 14:35~14:55
[Invited] Probing the Upper Atmosphere by Observing Meteors Over King Sejong Station Antarctica
Yongha Kim (Chungnam National University, Korea), Junseok Hong, Changsup Lee, Jeong-Han Kim, and Geonhwa Jee
As a meteor enters the Earth's upper atmosphere, it ablates due to friction with atmospheric particles at altitudes of 70 - 100 km and produces a plasma trail that contains an abundance of free electrons. These free electrons within the trail can produce the backscatter of a radar signal propagating perpendicular to the trail. By observing this back-scattered meteor echo, one can measure meteor decay time, radial drift velocity, and the spatial information of meteors (e.g., range and angle of arrivals). At King Sejong Station (KSS) Antarctica, a VHF meteor radar has been operating since its installation on March 2007 for the purpose of studying the upper atmosphere. The KSS radar consists of 1 transmitter, 5 receivers, data acquisition systems, and radar control/analysis software. The radar operates at 33.2 MHz, using a solid state transmitter with a peak power of 8 kW initially and upgraded to 12 kW in 2012. The KSS meteor radar has detected ~20,000 and ~30,000 meteors per day at a peak power of 8 kW and 12 kW, respectively, which varies with season as well as with local time. Analyses of the meteor echo data have produced valuable scientific information such as temperatures near mesopause and wind profiles at altitudes of 80 - 100 km day and night for full year around regardless of weather conditions. We have devised more accurate method of determining temperature from detected meteor decay times and presented continuous seasonal temperature variation in the high latitude mesosphere, where optical methods cannot monitor temperatures due to extended daylights during summer. We also discover strong wave activities in the upper atmosphere over the Antarctic peninsula from our wind measurements from the analysis of meteor echoes. The KSS meteor radar continues to produce valuable data not only for upper atmospheric studies but also for meteor science.
[B3B-1-4] 14:55~15:10
CME, Dynamo Effect and Their Effect on Auroras
Karan Bhatta (St. Xavier's College, Nepal) and Kishor Acharya
The Sun and the Earth with their inextricable interactions produce a wide number of phenomena and auroras happen to be one such visually amazing phenomenon. Much has been speculated about this visual treat which is caused by particle interaction between the Sun and the Earth on molecular, atomic and ionic scale. In my paper I have shed light regarding some scientific findings about auroras in two ways -firstly by expounding on how coronal mass ejections trigger the movement of solar wind which in turn acts as sources for the production of auroras and secondly by explaining the interaction between the solar wind and the magnetosphere commonly referred to as the dynamo action. In effect, these two factors give rise to auroras and also control their directions and frequency of occurrence. All in all, such grandeur vistas are not simply restricted to the Sun and the Earth but are a common occurrence in any star-planet system where the planet has a magnetic field strength comparable to that of the Earth.
[B3B-1-5] 15:10~15:25
The Daejeon 40.8 MHz VHF Radar Observations of the E- and F-Region Field-Aligned Irregularities in the Middle Latitude
Young-Sil Kwak (Korea Astronomy and Space Science Institute, Korea), Tae-yong Yang, Hyosub Kil, Woo Kyoung Lee, and Jae-Jin Lee
The electron density irregularities in the ionosphere cause diffraction of the radio waves that can be responsible for scintillation, fading, and disruption of the propagating signals. For this practical importance, significant efforts have been made to establish information on the occurrence climatology of such irregularities, to understand the onset conditions of such irregularities, and to predict or avoid the impact of these irregularities on the society. A 40.8 MHz VHF radar was built at Daejeon (36.18°N, 127.14°E, 26.7°N dip latitude) in South Korea aiming at continuous monitoring of middle-latitude field-aligned irregularities (FAIs) in the Far East Asian sector. The radar, which consists of 24 Yagi antennas, observes the FAIs using a single beam with a peak power of 24 kW. The radar has been operated continuously since December 2009 and provides a unique opportunity to investigate the climatology of the mid-latitude FAI activities. In this talk, we introduce the first ionospheric VHF radar experiment in South Korea and report characteristics of the mid- latitude E- and F-region FAIs. And also we report the seasonal variations of the mid-latitude ionospheric FAIs based on the continuous and long-term observations of the Daejeon VHF radar.
Session: [B3B-2] S2 : Interstellar Matter, Star Formation and the Milky Way Date: August 20, 2014 (Wednesday) Time: 14:00~15:25 Room: Room B (Room 103) Chair: Hauyu Baobab Liu (Academia Sinica Institute of Astronomy and Astrophysics)
[B3B-2-1] 14:00~14:20
[Invited] Dynamics of Filamentary Molecular Clouds: A Galactic View of Star Formation
Shu-ichiro Inutsuka (Nagoya University, Japan)
Recent observations of molecular clouds have revealed central roles of filamentary clouds in star formation processes. On the other hand, the formation and evolution of filamentary molecular clouds have been studied extensively in the past decades. This review explains the current understanding of the dynamics of filamentary molecular clouds and its implication to an overall picture of star formation in the Galaxy. The formation of filamentary molecular clouds can be understood in the context of cloud formation by external compression. Recent high-resolution magneto-hydrodynamical simulations of two-fluid dynamics with cooling/heating and thermal conduction have shown that the formation of molecular clouds requires multiple episodes of supersonic compression. This finding enables us to create a scenario of molecular cloud formation as the interacting shells or bubbles in the galactic scale. We can estimate the ensemble-averaged growth rate of the individual molecular cloud, and predict the mass function of molecular clouds. This picture naturally explains the accelerated star formation over many million years that was previously reported by stellar age determination in nearby star forming regions. Recent claim of cloud-cloud collision as a mechanism of forming massive stars and star clusters can be naturally expected in this scenario.
[B3B-2-2] 14:20~14:40
[Invited] The Processing of the Clumpy Molecular Gas in the Galactic Center and the Star-Formation
Hauyu Baobab Liu (Academia Sinica, Taiwan), Young Chol Minh, and Elisabeth Mills
The universality of the star formation laws has been widely investigated in extragalactic studies. When taking a closer look, these star formation laws may represent merely the weighted media for the large number of observed molecular clouds. Ultimately, the high precision observations may allow us to parametrize the details about how the star formation rate and efficiency are deviated from the laws, because of the different physical conditions in the natal molecular clouds. Preliminary hints may first be provided by observing the environments with the extreme physical conditions. The ~200 pc Galactic Central Molecular Zone (CMZ) provides the unique laboratory to resolve the star-forming molecular clouds around the supermassive black hole with the sub-parsec scale resolutions, thanks to the proximity. The high molecular gas temperature and the largely non-virialized gas motions in these clouds present the most extreme environment for star formation. The previous observations on molecular cloud M0.25+0.01 in the CMZ have reported the ~2 orders of magnitude smaller star-forming efficiency than the molecular clouds in the rest of the Galactic disk. In my talk, I will review the recent state-of-the-art mapping observations on the central ~20 pc area in the Galactic Center, which are the star-forming regions nearest to the central supermassive black hole Sgr A*. These observations include the Green Bank 100m Telescope (GBT) observations of the CS/SiO 1-0 lines and several ammonia hyperfine line transitions, the Karl G. Jansky VLA (JVLA) mosaic of ammonia hyperfine line transitions, and the large Submillimeter Array (SMA) 157-pointings mosaic of the 0.86 mm dust continuum emission as well as several warm and dense molecular gas tracers. We have resolved several filamentary gas streams, which follow highly eccentric Keplerian orbits around the central supermassive black hole (SMBH) Sgr A*, and the 2-4 pc scale circumnuclear disk (CND). Some of these gas streams appear to be well connected with the CND. Rather than being a quasi-stationary structure, the CND may be dynamically evolving, incorporating the inflow via exterior gas streams, and feeding gas toward the center. Combining the
GBT data with data from the JVLA covering clouds in the central ten parsecs, we are able to construct new maps of their temperature structure on tenth of a parsec size scales. We also see for the first time evidence of cooler and less turbulent clumps of gas embedded within these clouds. In addition, the unprecedentedly large field-of-view and the high angular resolution of our SMA dust image allow the identification of abundant 0.1- 0.2 pc scale dense gas clumps. Simple calculations suggest that the identified clumps can be possibly the pressurized gas reservoir feeding the formation of 1-10 solar-mass stars. We propose that these gas clumps are the most promising candidates for ALMA to resolve high-mass star-formation in the Galactic center.
[B3B-2-3] 14:40~14:55
The Role of Ridges in High Mass Star Formation: Super Filaments Hosting Protostars
Tracey Hill (Joint ALMA Observatory, Chile), Frederique Motte, Pierre Didelon, Quang Ngyuen Luong, Philippe Andre, Martin Hennemann, and V. Minier
High mass star formation and evolution is still a process that is not well understood, which is largely attributed to the clustered and embedded nature in which high-mass stars form. The Herschel Imaging Survey of OB Young Stellar Objects (HOBYS; Motte, Bontemps and Zavagno), aims to study the earliest stages of high- mass star formation and evolution as well as the environments in which they form. High mass stars require a greater reservoir of material than their (better studied) lower mass equivalents. We have identified the best locations from which high-mass stars can form - super filaments which we called ridges. Ridges are supercritical high-column density (>10^23 cm^-2) filaments which dominate their environment and serve as the preferential sites of high-mass star formation. For the first time, ridges provide an excellent mechanism through which high mass stars can form. We have identified a number of ridges in high-mass star forming complexes from HOBYS. Our earlier work suggested that ridges form through dynamical means such as converging flows and turbulence (e.g. Hill et al., 2011, Nguyen Luong et al., 2011) or through mergers of smaller filaments (e.g. Hennemann at al., 2012). Understanding how a ridge forms may allow prediction of how, where, and under what conditions high-mass stars form. It may be that high-mass stars are born as a result of the formation of the ridge itself, or that other factors, such as a bipolar nebula - as proposed by us (Minier et al. 2013) acts upon the ridge to trigger high- mass star formation. We present here the results of a census of ridges in HOBYS regions, which had the objective of identifying how a ridge forms from its natal molecular cloud and ultimately how they form young massive stars.
[B3B-2-4] 14:55~15:10
UKIRT Widefield Infrared Survey for Fe+
Jae-Joon Lee (Korea Astronomy and Space Science Institute, Korea), Bon-Chul Koo, Yong-Hyun Lee, Ho- Gyu Lee, Jong-Ho Shinn, Hyun-Jeong Kim, Yesol Kim, Tae-Soo Pyo, Dae-Sik Moon, Sung-Chul Yoon, Moo- Young Chun, Dirk Froebrich, Chris J. Davis, Watson P. Varr
The United Kingdom Infrared Telescope (UKIRT) Widefield Infrared Survey for Fe+ (UWIFE) is a 180 deg2 imaging survey of the first Galactic quadrant (7◦ < l < 62◦; |b| < 1.5◦) using a narrow–band filter centered on the [Fe II] 1.644 μm emission line. The [Fe II] 1.644 μm emission is a good tracer of dense, shock–excited gas, and the survey will probe violent environments around stars: star-forming regions, evolved stars, and supernova remnants, among others. The UWIFE survey is designed to complement the existing UKIRT Widefield Infrared Survey for H2 (UWISH2). The survey will also complement existing broad-band surveys. The observed images have a nominal detection limit of 18.7 mag for point sources, with the median seeing of 0.83′′. For extended sources, we estimate surface brightness limit of 8.1×10−20 Wm−2 arcsec−2. We will present the overview and preliminary results of this survey.
[B3B-2-5] 15:10~15:25
[Fe II] 1.64 µm Outflow Features Around Ultracompact H II Regions in the 1st Galactic Quadrant
Jong-Ho Shinn (Korea Astronomy and Space Science Institute, Korea), Kee-Tae Kim, Jae-Joon Lee, Yong- Hyun Lee, Hyun-Jeong Kim, Tae-Soo Pyo, Bon-Chul Koo, Jaemann Kyeong, Narae Hwang, and Byeong-Gon Park
Outflows play an important role in the star formation, especially during the mass accretion process onto the central compact object, because they remove the angular momentum from the ambient material. This functionality enables us to study the accretion process and its history by studying outflow phenomena. We here present the outflow features around ultracompact H II regions (UCHIIs) found on a quest for the ―footprint‖ outflow features of UCHIIs --- the features produced by the outflowing materials ejected during the earlier, active accretion phase of massive young stellar objects. We surveyed 237 UCHIIs in the 1st Galactic quadrant, employing the CORNISH UCHII catalog and UWIFE data. UWIFE is an imaging survey in [Fe II] 1.644 µm performed with UKIRT-WFCAM under ~ 0.8‖ seeing condition. The [Fe II] outflow features were found around five UCHIIs, one of which has a low plausibility. We interpret that the [Fe II] features are shock- excited, and estimate the outflow mass loss rates from the [Fe II] flux. The mass loss rate ranges ~ 1 x 10-6 − 4 x 10−5 Ms yr−1. We propose that the [Fe II] features might be the ―footprint‖ outflow features, but more studies are required to clarify it. This is based on the morphological relation between the [Fe II] and 5 GHz radio features, the outflow mass loss rate, the traveling time of the [Fe II] features, and the existence of several YSO candidates near the UCHIIs. The UCHIIs accompanying the [Fe II] features have a higher peak flux density. The outflow mass loss rate shows no significant correlation with the peak flux density, being limited by the small number of data. The fraction of UCHIIs accompanying the [Fe II] features, 5/237, is small when compared to the ~ 90 % detection rate of high-velocity CO gas around UCHIIs. We discuss some possible explanations on the low detection rate.
Session: [B3B-3] S7 : Historical Astronomy, Astronomy Education and Public Outreach Date: August 20, 2014 (Wednesday) Time: 14:00~15:30 Room: Room C (Room 104) Chair: Thilina Heenatigala (Universe Awareness)
[B3B-3-1] 14:00~14:15
The Need of Distant Learning for Astronomy Development in Indonesia
Avivah Yamani (langitselatan, Indonesia), Hakim. L. Malasan
Astronomy is a popular topic for public in term of astronomy phenomenon such as Occultation, Solar and Lunar eclipses or meteor showers. In term of education, astronomy also is popular as one of world‘s Science Olympiads. Social media as the new trend in communicating and connecting people, plays significant role to increase the number of astronomy community. Beyond IYA 2009, more and more astronomy activities have been done in many places in Indonesia. New astronomy community has been formed in several cities and public engagement also high in social media especially in Facebook and Twitter. As of September 2013, we had 25 active astronomy accounts on Twitter to share and educate public. In this paper, we will discuss about the lesson learn of astronomy outreach achievement in Indonesia and the need of citizen science project as a distant learning for public as part of astronomy development in Indonesia. We argue and propose that this project will be also important up to regional scope.
[B3B-3-2] 14:15~14:30
Enhancing the Teaching Astronomy in Schools Through Workshop for Teachers
Lau Chen Chen (National Space Agency of Malaysia, Malaysia)
The Malaysian Space Agency (ANGKASA) with cooperation of the Ministry of Education of Malaysia has been organized the Astronomy Workshop for Primary and Secondary School Teachers since 2008 at the National Planetarium. The workshop was organized to provide science teachers about the basic knowledge of astronomy in accordance to the school syllabus, with the hope that they acquiring sufficient knowledge and preparing them in the field of astronomy for enhancement of their teaching activities in school. In this workshop, teachers will be introduced experienced night sky simulations in our space theater, planetarium show, daytime and night time observation activities, hands on activities, visit to planetarium‘s observatory and exhibition gallery. Besides that, in this workshop they will share teaching experience with planetarium staffs. Educational materials also distributed to all the teachers as their reference in their teaching class. In this paper presentation, we would like to show how National Planetarium plays an important role to enhance teachers in teaching astronomy in schools.
[B3B-3-3] 14:30~14:45
Astronomy Education in India – Recent Trends in Human Resource Development
Harinder P. Singh (University of Delhi, India) and Ajit K. Kembhavi
India has made good progress recently in making astronomy attractive for aspiring astronomers by investing in mega astronomical projects, revamping astronomy programs in universities by devising and introducing astronomy courses as well as setting up of small observatories. At the same time, public outreach activities are being supplemented by opening new planetaria, science parks and museums to attract young students to science in general. New employment schemes are being implemented to attract young talent towards science teaching. We discuss the aspects of human resource generation efforts in India with special reference to
future needs of astronomy.
[B3B-3-4] 14:45~15:00
IAU AstroEDU: an Open-Access Platform for Peer-Reviewed Astronomy Education Activities
Thilina Heenatigala (Universe Awareness, SriLanka)
There are many sources of educational resources for astronomy across the world. The quality of these resources is highly variable making the effectiveness to the end-user an unknown quantity. They are not maintained or updated regularly and have a limited content review. To address these issues and more, astroEDU follows a peer-reviewed process similar to what scholarly articles are based on. Activities submitted are peer-reviewed by an educator and a professional astronomer which gives the credibility to the activities. astroEDU activities are open-access in order to make the activities accessible to educators around the world while letting them discover, review, distribute and remix the activities. astroEDU is endorsed by the International Astronomical Union meaning each activity is given an official stamp by the international organisation for professional astronomers.
Poster Session 15:00~15:30
Chair: Thilina Heenatigala (Universe Awareness) Harinder P. Singh (University of Delhi)
Session: [B3B-4] S4 : Galaxies, AGN and Cosmology Date: August 20, 2014 (Wednesday) Time: 14:00~15:30 Room: Room D (Room 105~106) Chair: Dharam (Vir) Lal (National Centre for Radio Astrophysics (NCRA-TIFR))
[B3B-4-1] 14:00~14:15
Formulation and Constraints on Late Decaying Dark Matter
N. Q. Lan (Hanoi National University of Education, Vietnam), N. T. Giang, G. Mathews, and I-S. Shu
We consider a late decaying dark matter model in which cold dark matter begins to decay into relativistic particles at recent epoch (z 1). A complete set of Boltzmann equation of dark matter particles is derived which is necessary to calculate the evolutions of their energy density and their density perturbations. We show that the large entropy production and associated bulk viscosity from such decays leads to a recently accelerating cosmology consistent with observations. We perform a constraint on the decaying dark matter model with bulk viscosity, by using MCMC method and the combined observational data from the CMB and type Ia supernovae.
[B3B-4-2] 14:15~14:30
Modeling the Surface Brightness of Early-Type Galaxies
Ing-Guey Jiang (National Tsing Hua University, Taiwan) and Li-Chin Yeh
It is observed through HST that the central surface brightness of early-type galaxies has an interesting diversity. Some have an obvious central flatten part, but the others do not. Thus, these galaxies could be classified into two types, i.e. core galaxies and power-law galaxies. In order to explain this diversity, we propose and construct dynamical models with supermassive binary black hole which could lead to the observational surface brightness, such as those described by Nuker law or Sersic law. After considering the mass and separation of supermassive binary black hole, and also the projection angle, these models could be useful for interpretations of future observational data. Moreover, in reverse, these models could also become good tools to constrain the mass and separation of supermassive binary black hole from the observational data of surface brightness of galaxies.
[B3B-4-3] 14:30~14:45
Large Gpc Volume Simulations of Reionization Based on Semi-Analytic Galaxy Formation Models
Hansik Kim (The University of Melbourne, Australia), J. Stuart B. Wyithe, Jaehong Park, G. B. Poole, and C. G. Lacey
Redshifted 21cm measurements of the structure of ionised regions that grow during reionization promise to provide a new probe of early galaxy and structure formation. One of the challenges of modelling reionization is to account both for the sub-halo scale physics of galaxy formation and the regions of ionization on scales that are many orders of magnitude larger. To bridge this gap we _rst calculate the statistical relationship between ionizing luminosity and Mpc scale overdensity using detailed models of galaxy formation computed within relatively small volume (~100Mpc/h), high resolution dark matter simulations. We then use a Monte- Carlo technique to apply this relationship to reionization of the intergalactic medium within large volume dark matter simulations (>1Gpc/h). The resulting simulations can be used to address the contribution of very large scale clustering of galaxies to the structure of reionization, and show that volumes larger than 500Mpc/h are required to probe the largest reionization features.
[B3B-4-4] 14:45~15:00
HST and LAMOST Discover a Dual Active Galactic Nucleus in J0038+4128
Huang Yang (Peking University, China), Liu xiaowei, Yuan Haibo, Xiang Maosheng, and et al.
Over the past few years, many efforts have been spent on searching for the kiloparsec-scale active galactic nuclei (AGN) because such system can provide important clues to understand the co-evolution between the AGN activity and host galaxy. In the hierarchical ΛCDM cosmology, galaxies built up via mergers. Binary supermassive black holes (SMBHs) are natural outcomes of galaxy mergers, since almost all massive galaxies are believed to host a central SMBH. In the gas rich case, the strong tidal interactions caused by galaxy mergers can trigger the active galactic nucleus (AGN) by sending a large amount of gas to the central regions. A dual AGN could emerge if the two merging SMBHs are both simultaneously accreting gas in a gas- rich major merger. However, up to now, no more than 20 of close dual AGNs (separations between 1 and 10 kpc) are found. Recently, we report the discovery of a new dual AGN in J0038+4128 with a spatial separation of 4.7 kpc based on the HST images, UV spectra and LAMOST optical spectra. One of them is the Seyfert 1 galaxy with broad emission lines and another one is the Seyfert 2 galaxy with narrow emission lines only. In the HST U-band image, two pairs of bi-symmetric spiral arms are detected in a binary AGN system for the first time. The results are consistent with the numerical simulations of Di Matteo et al. (2005). Being one of a few confirmed kiloparsec-scale dual AGNs exhibiting a clear morphological structure of the host galaxies, J0038+4128 provides a unique opportunity to study the co-evolution of the host galaxies and their central supermassive black holes undergoing a merging process.
[B3B-4-5] 15:00~15:15
Simulated Star Formation Rate Functions at z ~ 4–7, and the Role of Feedback in High-z Galaxies
E. Tescari (University of Melbourne, Australia), A. Katsianis, J. S. B. Wyithe, K. Dolag, L. Tornatore, P. Barai, M. Viel, and S. Borgani
We studied the role of feedback from supernovae (SN) and black holes in the evolution of the star formation rate function (SFRF) of z ∼ 4–7 galaxies. We used a new set of cosmological hydrodynamic simulations, ANGUS (AustraliaN GADGET-3 early Universe Simulations), run with a modified and improved version of the parallel TreePM-smoothed particle hydrodynamics code GADGET-3 called P-GADGET3(XXL), that includes a self-consistent implementation of stellar evolution and metal enrichment. In our simulations both SN-driven galactic winds and active galactic nuclei (AGN) act simultaneously in a complex interplay. The SFRF is insensitive to feedback prescription at z > 5, meaning that it cannot be used to discriminate between feedback models during reionization. However, the SFRF is sensitive to the details of feedback prescription at lower redshift. By exploring different SN-driven wind velocities and regimes for the AGN feedback, we find that the key factor for reproducing the observed SFRFs is a combination of ‗strong‘ SN winds and early AGN feedback in low-mass galaxies. Conversely, we show that the choice of initial mass function and inclusion of metal cooling have less impact on the evolution of the SFRF. When variable winds are considered, we find that a non-aggressive wind scaling is needed to reproduce the SFRFs at z ≥ 4. Otherwise, the amount of objects with low SFRs is greatly suppressed and at the same time winds are not effective enough in the most massive systems.
[B3B-4-6] 15:15~15:30
Discovery of a Strong Lensing Galaxy Embedded In a Cluster at z = 1.62
Kenneth C. Wong (Academia Sinica Institute of Astronomy and Astrophysics, Taiwan), Kim-Vy H. Tran, Sherry H. Suyu, Ivelina G. Momcheva, Gabriel B. Brammer, Mark Brodwin, Anthony H. Gonzalez, Aleksi Halkola, Glenn G. Kacprzak, Anton M. Koekemoer, Casey J.
Gravitational lensing is a powerful tool for studying the mass structure of galaxies, including their mass profile slope and central dark matter fraction. However, strong lensing galaxies are increasingly rare at higher redshifts – only a handful of such systems at z > 1 are known. In this study, we identify a strong lensing galaxy in the cluster IRC 0218 that is spectroscopically confirmed to be at z = 1.62, making it the highest- redshift strong lens galaxy known. The lens is one of the two brightest cluster galaxies and lenses a background source galaxy into an arc and a counterimage. With Hubble Space Telescope grism and
Keck/LRIS spectroscopy, we measure the source redshift to be zS = 2.26. Using HST imaging in ACS/F475W, ACS/F814W, WFC3/F125W, and WFC3/F160W, we model the lens mass distribution with an elliptical power- law profile and account for the effects of the cluster halo and nearby galaxies.
Session: [B3B-5] S7 : Historical Astronomy, Astronomy Education and Public Outreach Date: August 20, 2014 (Wednesday) Time: 14:00~15:30 Room: Room E (Room 107) Chairs: Irina Voloshina (Sternberg Astronomical Institute) Nguyen Quynh Lan (Hanoi National University of Education)
[B3B-5-1] 14:00~14:10
Succeeding as a Female Astronomer: Peer Groups and Overcoming Impostor Syndrome and Unconscious Bias
Blakesley Burkhart (University of Wisconsin Madison, USA)
Women face special challenges on the road to becoming a professional astronomer. In this talk I will outline two major challenges for women in STEM fields, the imposter syndrome and unconscious bias and how to take steps to overcome these issues with the help of peer groups.
[B3B-5-2] 14:10~14:20
Women in Astronomy
Shova Kanta Lamichhane (Government of Nepal Ministry of Science , Nepal), Manisha Dwa, and Suresh Bhattarai
The mother of all sciences, Astronomy, has just started toddling in Nepal. Had not been mentioned before in any courses, has now been introduced in post graduate level for the last five years. While a very few number of female students ~ 5-10 % are enrolled in physics. Among those students, how many of them choose astronomy and the reasons behind choosing astronomy as their major subject will be presented in this paper in detail. This paper also presents the leading role of Nepal Astronomical Society (NASO) along with Nepal Academy of Science and Technology (NAST) and B.P. Koirala Memorial Planetarium, Observatory and Science Museum Development Board empowering women in the field of astronomy and space science as well as the trend of female enrollment in astronomy education in Nepal till date. This paper will also highlight the importance of empowering women in astronomy to encourage new generation towards science education in Nepal. A case study on women engagement and leadership on astronomy in Nepal to unveil the talents encouraging more female participation on astronomy activities in Nepal will be discussed in detail.
[B3B-5-3] 14:20~14:30
Women Astromers in India
G. C. Anupama (Indian Institute of Astrophysics, India)
Although still a relatively small percentage, the number of women astronomers in India has witnessed a steady growth over the years. This talk will provide a brief account of the women astronomers in India, highlighting the achievements of a few of them.
Session: [B3B-5] S5 : Compact Objects, High Energy and Particle Astrophysics Date: August 20, 2014 (Wednesday) Time: 14:00~15:30 Room: Room E (Room 107) Chair: Maurice van Putten (Sejong University)
[B3B-5-4] 15:00~15:15
Black Hole Binaries from Galactic Nuclei
Hyung-Mok Lee (Seoul National University, Korea) and Jongsuk Hong
Gravitational waves predicted by the general relativity almost 100 years ago have been implicated indirectly only by astrophysical observations such as the orbital evolution of binary pulsars. The advanced detectors of gravitational waves will become operational in a few years and they are expected to make direct detection of gravitational wave signal coming from merging of binaries composed of neutron stars or stellar mass black holes from external galaxies. Current estimates of the expected rate of merger event of neutron star or black hole binaries are based on very limited number of observed binary pulsars with careful considerations on the observational biases, stellar evolution, including binary phases, and dynamics of dense star clusters. Therefore these estimations vary several orders of magnitude depending on assumed parameters and models. We concentrate on the expected rates of the black hole binaries originated from galactic nuclei star clusters (NC) purely based on the dynamical considerations. The NCs with central supermassive black holes (SMBHs) are modeled stars representing the stellar mass BHs together with the additional potential due to the central black hole and bulge in the N-body simulations. In such an environment, binaries are predominantly formed by the gravitational radiation (GR) as a result of close encounters. Most of the binaries have very eccentric orbits (1-e ~10^-4) with very small presenter distances. The merging time after the formation of the binary is much shorter than any other dynamically relevant time scales. They will produce waveforms quite different from the ones with circularized orbits as they remain eccentric when they enter the aLIGO/Virgo bands. We find that the overall formation rates for BH-BH binaries per NC is 10^-10 per year for the Milky-Way-like galaxies, corresponding to order of 0.02 to 15 events per year within the aLIGO/Virgo horizons. However, several factors such as the dynamical evolution of the cluster, the variance of the number density of stars and the mass range of MBH give uncertainties by a large factor (more than two orders of magnitude).
[B3B-5-5] 15:15~15:30
The White Dwarf Luminosity, Mass and Age Functions as Revealed by the LAMOST Survey of the Galactic Anti-Center
Alberto Rebassa-Mansergas (Peking University, China), Xiaowei Liu, Haibo Yuan, Ruxandra Cojocaru, Enrique Garcia-Berro, and Santiago Torres
The white dwarf population observed by a given survey can be used to determine white dwarf space densities, which allows to obtain the white dwarf luminosity function (LF), mass function (MF) and age function (AF). This exercise has been applied in the past to several different surveys. However, the white dwarf samples from which the currently observed LF, MF and AF are built are the result of complicated target selection algorithms and it becomes impossible e.g. to derive accurate white dwarf formation rates. The LAMOST survey of the Galactic Anti-Center (GAC) follows a well-defined selection criteria aiming at providing spectra for all stellar sources in the GAC (including white dwarfs) so that they can be studied in a statistically meaningful way. This has a significant advantage over previous surveys because we can apply this well- defined selection criteria to a simulated white dwarf population and directly compare the resulting LF, MF and AF to the observed ones. This exercise is crucial to evaluate the completeness of the observed sample and to thus obtain true white dwarf space densities and formation rates. In this contribution I present and describe in detail the white dwarf LF, MF and AF as derived from the LAMOST survey of the GAC.
Session: [B3B-6] S6 : Observing Facilities and International Collaborations Date: August 20, 2014 (Wednesday) Time: 14:00~15:30 Room: Room F (Room 108) Chair: Hideyuki Kobayashi (National Astronomical Observatory of Japan)
[B3B-6-1] 14:00~14:15
[Invited] Status and Feature of East Asian VLBI Network
Hideyuki Kobayashi (National Astronomical Observatory of Japan, Japan), Yoshiaki Hagiwara, Se-Hyung Cho, Jongsoo Kim, Xiaoyu Hong, Zhiqiang Shen, and EAVN Team
East Asian VLBI network is under organizing as one of largest VLBI array in the world. Japan has VERA, VLBI exploration for Radio Astrometry, which consists of four 20-m telescopes. It has two-beam system to make simultaneous observations for two targets and phase referencing VLBI observations. Also Japanese VLBI network has been organized, which consists of 13 VLBI stations including VERA four stations. It makes high sensitivity VLBI observations at 22, 8 , and 6.7 GHz. Korea has KVN, Korean VLBI network, which consists of three 21-m telescopes. It has simultaneous multiband receivers for multi-frequency VLBI observations with 2,8,22,43,86, and 129 GHz. Chinese VLBI network has been organized for lunar satellite tracking, which consists of four VLBI stations. Moreover Shanghai 65-m telescope was constructed and is under commissioning. Shanghai 25-m and 65-m and Urumqi 25-m telescopes are joining European VLBI Network. Therefore East Asian VLBI network is organizing these arrays. Korea and Japan developed the new large scale VLBI correlator at Daejun, which has a capability of 16 station correlation with 8 Gbps data rate per station. East Asian VLBI network succeeded to detect fringes at 8 and 22 GHz with Japanese, Korean and Chinese stations. It is under commissioning to check the sensitivity, resolution and other feasibilities. East Asian VLBI network has 6,000 km extension and around 20 stations possibly, which is one of largest VLBI network at 6.7, 8, 22, and 43 GHz. We will show the possible feasibilities, current status and future schedule.
[B3B-6-2] 14:15~14:30
[Invited] Overview of Japanese VLBI Network and Science Results
K. Fujisawa (Yamaguchi University, Japan)
Japanese VLBI Network (JVN) is a VLBI network operated by National Astronomical Observatory of Japan together with seven universities. The network consists of more than 10 radio telescopes with diameter of 11 m to 64 m owned or operated by research institutions and universities. The baseline length of JVN ranges 50 - 2500 km, and the observation frequencies are 6.7 , 8 and 22 GHz. JVN started its operation in 2005 and there are about 20 published papers so far. Main subjects of research are AGNs and star forming regions by using masers as probes. From 2010, an effort to extend the VLBI network to the East Asia in cooperation with China and Korea has been made. A VLBI survey observation of methanol maser sources was published in 2014 as the first result of EAVN.
[B3B-6-3] 14:30~14:45
KVN Source-Frequency Phase-Referencing Observation of 3C 66A & 3C 66B
Guang-Yao Zhao (Korea Astronomy and Space Science Institute, Korea), Bong Won Sohn, Taehyun Jung, Maria Rioja, and Richard Dodson
In this presentation, I will introduce the ongoing KVN campaign of Source-Frequency Phase-Referencing (SFPR) observations of 3C 66A and 3C 66B. These two are both very interesting objects which show peculiar properties. Especially, 3C 66B was once argued to be harboring a SMBH binary at its center based on the
position measurements of the jet core with respect to the core in 3C 66A. However, recent analysis show non- stationarity of the core exist in both sources, which disfavors the binary scenario. Core-shift measurements would be important to understand the non-stationarity of the core. The simultaneous multi-frequency receiving capability of KVN makes it the best array to study the core-shift related sciences. In the KVN campaign, two more sources are observed as secondary reference calibrators and each source was observed at 22, 43, and 86 GHz simultaneously. The core-shift measurements are found to be affected by structural blending effect because of the large beamsize, but this can be corrected with higher resolution maps (e.g. KAVA maps). The future multi-epoch results will enable us to locate the central SMBH in each source and trace its possible motion.
[B3B-6-4] 14:45~15:00
[Invited] Submm VLBI Activities in Taiwan
Makoto Inoue (Academia Sinica Institute of Astronomy and Astrophysics, Taiwan)
A group of Very Long Baseline Interferometry (VLBI) was formed in 2009 in Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). Although several universities have a radio astronomy group or an astronomy department, VLBI activities are only in ASIAA so far. Discussion on collaboration is occasionally made between the VLBI group and the university groups or individual researchers, but it is not so actively coordinated yet. Consequently, this talk will begin with a brief history of the VLBI group in ASIAA, followed by its present status. In 2011, ASIAA VLBI group was awarded the ALMA prototype antenna, collaborating with the Smithsonian Astrophysical Observatory (SAO), MIT Haystack Observatory, and National Radio Astronomy Observatory (NRAO). We proposed to deploy it as a submm VLBI station at the Summit Station in Greenland, to get the first shadow image of the Super Massive Black Hole (SMBH) in M87. The shadow image is expected to be observed against bright environments of accretion flows and possibly jets, proving a direct evidence of the existence of black hole. As the size and shape of the shadow depends on the mass and spin, respectively, we could directly measure these fundamental parameters of the SMBH. Together with the study of bright environments, the observation will enable us to open new windows to investigate General Relativity in a strong gravity field, accretion mechanism of flows, launching mechanism of relativistic jets, etc. Our VLBI group is studying these and the relativistic jet physics. The telescope in Greenland (named as the Greenland Telescope: GLT) could achieve the angular resolution of 20 micro arcsec (µas) at 350 GHz, combined with the Phased ALMA in Chile and the Submillimeter Telescope (SMA) in Hawaii. As the size of the shadow image is expected to be about 40 µas for the M87 SMBH, it is very convincing to be able to image the shadow. The Phased ALMA will provide high sensitivity and angular resolution with the GLT. ASIAA jointly operates the SMA and closely involved in the ALMA project, and we have a lot of experiences on submm observations. The GLT has been retrofitted for the cold environment in Greenland. These components will be shipped to Greenland in 2015 and reassembled at Thule, a North West coast of Greenland. We are planning to make commissioning tests and some early sciences there. Parallel to our telescope and site arrangements, our VLBI group participates in the ALMA Phase-up Project. For this project, we have a small set of a computer cluster to run the DiFX software correlator on it. Based on this experience, we are planning to have a DiFX system by ourselves, or in collaboration with other correlator groups, to process the submm VLBI observations. In this region, there are active groups on VLBI and its sciences, and possible collaborations will be also discussed.
[B3B-6-5] 15:00~15:15
[Invited] The Korean VLBI Network and the Highlights of its Scientific Results
Jongsoo Kim (Korea Astronomy and Space Science Institute, Korea) and KVN Team
We introduce a very long baseline interferometry (VLBI) network in Korea. The Koran VLBI network (KVN) is the first millimeter-dedicated VLBI network in East Asia. It consists of three 21 m radio telescopes with baseline lengths in a range of 305–476 km. It has unique capability to perform VLBI observations at 22, 43, 86, and 129 GHz bands, simultaneously. The observational data have been processed using a distributed FX software correlator or a hardware correlator developed by Korea and Japan. The first fringes of the KVN were obtained at 22 GHz on 2010 June 8. Since then, VLBI observations using the KVN have been routinely done. From the 2014A semester, the KVN was open to the East Asian community. We introduce highlights of science cases of the KVN such as detection of 44 GHz methanol masers, polarization observations of
Zeeman splitting of maser lines, fringe detection of 129 GHz SiO masers from evolved stars
[B3B-6-6] 15:15~15:30
[Invited] VERA Science Results
M. Honma (National Astronomical Observatory of Japan, Japan)
We introduce the recent results of science results from VERA (VLBI Exploration of Radio Astrometry). The VERA is a dedicated array to explore the 3-dimensional structure and dynamics of the Galaxy based on high- accuracy VLBI astrometry, and since 2007 we have been observing Galactic H2O and SiO masers to measure their accurate parallaxes and proper motions. In this talk, we briefly review the current status of the VERA project, and then show the highlights of the recent results such as determinations of Galactic parameter and also spiral arm structures. We also briefly introduce our recent works for building the East Asian VLBI Network (EAVN) including Japanese, Korean and Chinese radio telescopes and show some early science results such as the mapping of methanol maser sources as well as faint AGN jets.
Session: [B3C-1] S1 : Solar System and Sun-Earth Interactions Date: August 20, 2014 (Wednesday) Time: 16:00~17:30 Room: Room A (Room 101~102) Chair: David Ruffolo (Mahidol University)
[B3C-1-1] 16:00~16:15
Probing the Energy Build-Up and Trigger Mechanism of a X1.2 Class Solar Flare on May 15, 2013
Aabha Monga (Aryabhatta Research Institute of Observational Sciences (ARIES), India), Arun Awasthi, Wahab Uddin, and Ramesh Chandra
In this paper, we study the energy build-up and trigger processes responsible for a X1.2 class solar flare that occurred in NOAA AR 11748, having magnetic complexity βγδ on May 15, 2013. The flare was well observed by ground based (Hα ARIES, Nainital) and space borne(SDO, STEREO). The flare shows two ribbons structures. Morphology of flare ribbons shows that the brightening propagates along the southern ribbon. We have noticed several H-alpha kernels that shows different spatially and temporally evolutionary behavior. On the contrary, we do not find filament associated with this event. Therefore, to explore the driver of instability leading to this highly energetic flare, we study the morphological evolution of the active region SDO and STEREO data. We also study the evolution of photospheric magnetic field parameters from SDO/HMI magnetograms in conjunction to the E/UV emission. From AIA EUV images, we note sets of coronal loops over the active region, which show upward motion with the time. We explicitly note mass ejection and disruption of coronal loops. We make a height-time study of the loop eruption in order to understand the acceleration mechanism. From this study, we infer that this flare onset site was beneath the uprising coronal loops. A CME is also associated with this flare as observed from LASCO and STEREO images.
[B3C-1-2] 16:15~16:30
Acceleration of Solar Energetic Particles during Decline Phase of SC-23
Ahmed A. Hady (Cairo University, Egypt)
The solar energetic particles (SEP‘s) could be accelerated to higher energies of order of MeV per nucleon. A modified model for SEP‘s acceleration has been given and applied for storms event during the decline phase of solar cycle 23. The estimated values of the solar magnetic field during the solar particle event were introduced. The solar magnetic field describes a sophisticated feature of discrete sectors/regions over the period that starts from 28 October 2003 to 4 November 2003. The applications of the suggested model on the solar particle event show that a homogeneous structure is in agreement with the observations. The acceleration time is calculated, where the energy losses due to the different physical processes are entirely neglected. The combination of the direct acceleration and the well-known Fermi mechanisms verifies the observed spectrum.
[B3C-1-3] 16:30~16:45
Classification of SPEs According to Their Origins and Acceleration Trends Using the Multi-Channel Observation
R.-S. Kim (Korea Astronomy and Space Science Institute, Korea), K.-S. Cho, S.-C. Bong, and Y.-D. Park
To investigate characteristics of the solar proton event (SPE) and its association with other solar eruptive phenomena, we examined 42 SPEs observed from 1997 to 2012, which have clear information of associated flares, coronal mass ejections (CMEs) and interplanetary (IP) type II radio bursts. By applying the velocity dispersion analysis to the proton flux observations in the multi-energy channels from 13 to 130 MeV detected
by SOHO/ERNE, we estimated the onset times of proton flux increase at the solar vicinity on the respective energy levels, and compared it with the onset times of flares and type II radio bursts, and the first appearance times of CMEs in the LASCO field of view. The results are as follows: (i) among 42 SPEs, 13 events (31%) start to accelerate during the are X-ray intensity is increasing, and for the other 29 SPEs (69%), the onset times well agree with the first appearance time of CMEs; (ii) there are different trends of the onset sequence between the are associated events and CME associated events. The former show the accelerations starting from the lower energetic pro- tons, while the latter show the accelerations from the either energy ranges, starting from the higher (13 events, 31%) or the lower (9 events, 21%), and sometimes simultaneous accelerations for all energy ranges within 10 minutes (7 events, 17%); and (iii) the are associated SPEs tend to have large flux enhancements in a short time, while the CME associated SPEs tend to have relatively weak and slow flux enhancements. Although we classified the SPEs by the onset sequences and the acceleration trends based on the velocity dispersion analysis, our results well consistent with the conventional classification based on the profile of proton flux, such as impulsive and gradual SPEs.
[B3C-1-4] 16:45~17:00
3D Simulation of Galactic Protons and Electrons Modulation for Fisk-Parker Hybrid Heliospheric Magnetic Field Pattern
Zbigniew Kobylinski (Polish Air Force Academy, Poland), Ali Ajabshirizadeh, and Tengiz Botchorishvili
The structure of heliospheric magnetic field (HMF) is discussed till nowadays and remains an unsolved problem. Parker spiral pattern was confirmed by measurements in the heliospheric equatorial plane. The measurements of the Ulysses spacecraft at high latitudes exhibit that this model would be improved especially for the period of solar minimum. The way to understand Ulysses results led to the development of HMF Fisk pattern. In this study papers published up to the present on this subject are reviewed. A steady state 3D transport equation with drift included is solved in the spherically symmetric heliosphere bounded at the distance of 80 AU in order to compare the modulation of galactic protons and electrons in standard Parker spiral pattern and in simplified Fisk‘s field with latitude-dependent solar wind i.e. Schwadron- Parker hybrid field In calculations the parallel and perpendicular diffusion coefficients are proportional to 1/B, anti-symmetric element of the diffusion tensor has the form derived by Forman et al. under the assumption of week-scattering.. We assume also that the two circular coronal holes are localized near the poles with the central points that are offset from the rotation axis by the angle 100.The computed spectra and gradients are presented. The results for Fisk‘s type IHF are consistent, in principle, with measurements at high latitudes.
Poster Session 17:00~17:30 Chairs: David Ruffolo (Mahidol University) Kyungsuk Cho (Korea Astronomy and Space Science Institute)
Session: [B3C-2] S2 : Interstellar Matter, Star Formation and the Milky Way Date: August 20, 2014 (Wednesday) Time: 16:00~17:30 Room: Room B (Room 103) Chair: Shu-ichiro Inutsuka (Nagoya University)
[B3C-2-1] 16:00~16:20
[Invited] Radio Astrometric Observations and the Galactic Constant as Basis of the Galactic Kinematics Study
Takumi Nagayama (National Astronomical Observatory of Japan, Japan), Toshihiro Omodaka, Toshihiro Handa, Hideyuki Kobayashi, and Ross A. Burns
We made phase-referencing Very Long Baseline Interferometry (VLBI) observations of Galactic 22GHz H2O maser sources with VLBI Exploration of Radio Astrometry (VERA). We verified the positional measurement accuracy of VERA using the G48.99-0.30 and G49.19-0.34 astrometric observations. The measured positional systemic error in R.A. and Decl. of (23, 31) micro arcsec for G49.19-0.34 is dominated by tropospheric contribution in Earth's atmosphere. That of (23, 53) micro arcsec for G48.99-0.30 depends on a tropospheric contribution and a maser structure effect. The formal positional error by the thermal noise is significantly smaller than these systemic positional errors. VERA phase-referencing observations could achieve the positional accuracy of a few tens of micro arcsec in both R.A. and Decl. Directions for point-like and bright sources at high elevation. We measured the parallax distances of ON1, ON2N, G48.99-0.30, G49.19-0.34, and IRAS 20143+3634 which are located near the tangent point and the Solar circle, to be 2.47+/-0.11 kpc, 3.83+/-0.13 kpc, 5.62+/-0.59 kpc, 4.74+/-0.39 kpc, and 2.72+/- 0.31 kpc respectively. The angular velocity of the Galactic rotation at the Sun's position (i.e. the ratio of the Galactic constants) is derived using the measured parallax distances and proper motions of these sources. The derived value of 28+/-2 km/s/kpc is consistent with recent values obtained using VLBI astrometry but most likely 10% larger than the International Astronomical Union (IAU) recommended value of 25.9 km/s/kpc = (220 km/s) / (8.5 kpc).
[B3C-2-2] 16:20~16:40
[Invited] Water Maser Outburst in W49N: a Multi-Transition Study
Busaba Hutawarakorn Kramer (Max Planck Institute for Radio Astronomy, Germany), Karl M. Menten, Tomasz Kaminski, and Alex Kraus
Recently, a major (~ 80,000 Jy) flare of the high velocity (violet) component of the 22.2 GHz 616-523 water (H2O) maser line in the most luminous Galactic H2O maser source W49N was reported by A. Tolmachev (The Astronomer‘s Telegram, 28 January, 2014). In 2014 early May we have carried out nearly simultaneous observations of several H2O transitions: (1) the 22.2 GHz line using the Effelsberg 100-m radio telescope, (2) the 183 GHz 313-220 transition using the IRAM 30-m telescope, as well as the (3) 325 GHz 515-422, (4) 321 GHz 1029-936 and (5) 475 GHz 533-440 transitions all using the APEX 12-m submillimeter telescope. For the last line, our data represent its first detection in a star- forming region. We have also performed interferometric observations of the 22.2 GHz transition using the NRAO Very Long Baseline Array (VLBA) and of the 321 and 325 GHz transitions using the Submillimeter Array (SMA). One remarkable result is the our detection of very high velocity emission features in several transitions. In this meeting, we will report the results from the single dish observations. Studying these multiple masing transitions in conjunction with theoretical modeling of their excitation places strong constraints on the physical conditions of the masing gas and in particular allows the examination of various models accounting for these high velocity features.
[B3C-2-3] 16:40~16:55
Trigonometric Parallaxes of Star Forming Regions in the Perseus Spiral Arm
Y. K. Choi (Korea Astronomy and Space Science Institute, Korea), K. Hachisuka, M. J. Reid, Y. Xu, A. Brunthaler, K. M. Menten, and T. M. Dame
Although our Galaxy is known to be a barred spiral galaxy, it is very difficult to determine its structure owing to our location within its disk. Using Very Long Baseline Interferometry (VLBI), one can measure trigonometric parallaxes to massive star forming regions with accuracies of order 10 microarcseconds. The Bar and Spiral Structure Legacy (BeSSeL) Survey is a National Radio Astronomy Observatory (NRAO) key science project that aims to study the spiral structure and kinematics of our Galaxy by measuring trigonometric parallaxes and proper motions of hundreds of massive star forming regions with the Very Long Baseline Array (VLBA). We report trigonometric parallaxes and proper motions of water masers for 12 massive star forming regions in the Perseus spiral arm of the Milky Way as part of the BeSSeL Survey. Combining our results with 14 parallax measurements in the literature, we estimate a pitch angle of 9.9 +/- 1.5 degrees for a section of the Perseus arm. The 3-dimensional Galactic peculiar motions of these sources indicate that on average they are moving toward the Galactic center and slower than the Galactic rotation.
Poster Session 16:55~17:30 Chair: Shu-ichiro Inutsuka (Nagoya University)
Session: [B3C-3] S7 : Historical Astronomy, Astronomy Education and Public Outreach Date: August 20, 2014 (Wednesday) Time: 16:00~17:30 Room: Room C (Room 104) Chair: Hidehiko Agata (National Astronomical Observatory of Japan)
[B3C-3-1] 16:00~16:15
[Invited] Conduction of Astronomical Activities to Motivate Students in Public Schools of Nepal
Sarita Baral (Takshashila Academy, Nepal)
Despite the favorable climatic and geographical conditions, research and development of the astronomy in Nepal is very limited. Nepal has to do lots of works to aware the astronomy for its development. To increase the astronomical awareness there should be activities in School. School activities will aware not only to children but also to the school teachers in a practical way. If the school children are interested in astronomy they continue their study in astronomy. They conduct research and development in this field. Hence It has been believed that school education is very important to make foundation in the development of astronomy. In this regard, the curriculum of science of the class 8, 9 and 10 has been thoroughly reviewed and the teaching methodology has been inquired. Considering the gaps of teaching at class and the practical works of Astronomy, practical ways and materials such as fundamental of telescope and its use, measures and precautions to view the astronomical objects in normal days or in astronomical events such as eclipse, transits has been considered in the project. Posters, pamphlets, astronomy books, Small telescope, solar glasses are used and distributed to the selected four public schools of Nepal.
[B3C-3-2] 16:15~16:30
[Invited] Current Status of Astronomical Educational Observatories Activities in Uzbekistan
Ehgamberdiev Sh. (Ulugh Beg Astronomical Institute of the Uzbek Academy of Sciences, Uzbekistan), Asfandiyarov I., Baijumanov A., and Tillaev Yu.
It is difficult to imagine a modern university or college lack of observatory for the reason that astronomy is not only an academic science, but also the main factor in building world view of a human being. The Ulugh Beg Astronomical Institute put forward initiative to build in Uzbekistan the network of educational observatories equipped with professional class telescopes. There are five educational observatories at this moment which are fully operational and one more observatory is going to be built by the end of 2014 in Nukus, Karakalpakstan (Aral see area). The network will provide all universities and pedagogical institutes where astronomy is taught with telescopes adjusted for educational purposes to have practical courses on observational astronomy. Geographical location of Uzbekistan and its astroclimate quality make it unique place for astronomical programs requiring continuous (without day and night interruptions) observations of celestial objects. Due to spread of the country in longitudinal direction atmospheric front crosses it in about 2 days. The location of observatories around the country is ideal for performing uninterrupted for weather conditions astronomical observations. After equipping with CCD-cameras in near future the network will be feasible to join campaigns on follow up observation of space mission targets. It is also significantly improve education in the institutions where observatories were opened.
[B3C-3-3] 16:30~16:45
[Invited] Chinese Ancient Poetry Astrophotography Competition
Bing Li (Beijing Planetarium, China)
Our ancestors are closer to the night sky than we are. The sky nearly never changes. The OAD 2013 project Chinese Ancient Poetry Astrophotography Competition encourages more people to take pictures of the night sky according to Chinese ancient poems. And then let more people appreciate the night sky through the lenses of that beautiful poetry! Kevin Govender, the director of IAU OAD said, ' This project that Bing Li is leading is a perfect marriage between our cultural astronomical roots and the modern technology we use to observe the stars. I will share how we design and develop the project and show some beautiful works of the competition.
[B3C-3-4] 16:45~17:00
PULSE@Parkes: Hands-On Radio Astronomy for High Schools
R. Hollow (CSIRO Astronomy & Space Science, Australia), G. Hobbs, R. Shannon, and M. Kerr
Since 2007 over 1,100 students across Australia and in the UK, Netherlands, Japan and USA have participated in this innovative program run by CSIRO Astronomy and Space Science (CASS). PULSE@Parkes is a free educational program in which high school students control the 64m Parkes radio telescope remotely via the internet to observe pulsars. Following a background talk presented ahead of the observing session students working in small groups students decide which pulsars to observe, control the telescope and gather data. The data is archived and freely and publicly available from the web. Students use the data to determine the distance to pulsars during the session via an online module. They can also use it post-observing session for open-ended student investigations. An integral part of the program is the interaction between the high school students and the professional scientists and PhD students. Data is also utilised by CASS astronomers for other ongoing scientific projects including pulsar timing and the study of nulling and intermittent pulsars. Social media such as Twitter and streaming data via web browser displays allow us to involve a wider audience beyond the students during observing sessions. We outline some of the key points learnt to date in implementing and delivering the project and highlight what makes for effective educational engagement. Plans for future developments are presented along with the potential for expanding a regional or global network of high school students using data from major radio astronomy facilities for student investigations.
Poster Session 17:00~17:30 Chairs: Hidehiko Agata (National Astronomical Observatory of Japan) Thilina Heenatigala (Universe Awareness)
Session: [B3C-4] S4 : Galaxies, AGN and Cosmology Date: August 20, 2014 (Wednesday) Time: 16:00~17:30 Room: Room D (Room 105~106) Chair: Tzu-Ching Chang (Academia Sinica Institute of Astronomy and Astrophysics)
[B3C-4-1] 16:00~16:20
[Invited] FastSound: Probing the Origin of Cosmic Acceleration by Galaxy Clustering at z ~ 1.3 with Subaru/FMOS
Tomonori Totani (The University of Tokyo, Japan)
I will introduce the FastSound project, a galaxy redshift survey for the purpose of cosmology using Subaru/FMOS. The survey covers ~30 deg^2 in total in the redshift range of z=1.2-1.5 by detecting H alpha emission lines in near-infrared, with an expected galaxy number of ~5,000. The main science goal is to detect the redshift space distortion effect for the first time at this redshift range, and measure the structure growth rate of the universe, which is sensitive to the gravity theory and hence the mystery of the cosmic acceleration.
[B3C-4-2] 16:20~16:35
Infrared Medium Deep Survey
Myungshin Im (Seoul National University, Korea), Soojong Pak, Jae-Woo Kim, Seong-Kook J. Lee, Marios Karouzos, Ji Hoon Kim, Won-Kee Park, Yiseul Jeon, Minhee Hyun, Changsu Choi, Yongmin Yoon, Yongjung Kim, Hyunsung Jun, Dohyeong Kim, Yoon Chan Taak, Gieson Baek, Hyeongju Jeong, Juhee Lim, Eunbin Kim, Nahyun Choi, Hye-In Lee, K. M. Bae, and Seunghyuk Chang
We describe the survey strategy, the current status and the early science results from the Infrared Medium- deep Survey (IMS). IMS is a near-infrared imaging survey using the United Kingdom Infared Telescope (UKIRT) and CQUEAN instrument on the 2.1m telescope at the McDonald observatory. IMS is aimed to understand the formation and the evolution of quasars and galaxies at high redshift, and study transient and time-variable objects such as gamma-ray bursts, supernovae, and young stellar objects. The survey uses a multi-tier structure, with deep imaging of 100 deg2 using UKIRT to the depth of 23 AB mag (5-sigma) in J and Y-band, and shallower imaging of interesting sources such as quasars at z = 5.5 quasars and galaxy clusters using the CQUEAN camera. This talk will introduce the survey design, and the instrument development, and science highlights of IMS. The science highlights will include the discovery of high redshift quasars, galaxy cluster candidates at z > 1, GRBs, and other interesting sources uncovered from the survey.
[B3C-4-3] 16:35~16:50
Dark Matter Cores in Dwarf Galaxies
Se-Heon Oh (The University of Western Australia, Australia), Deidre Hunter, Elias Brinks, and Bruce Elmegreen
We present high-resolution rotation curves and mass models of rotation-dominated 26 dwarf galaxies from ‗Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey‘ (LITTLE THINGS). LITTLE THINGS is an high-resolution (~6′′ angular; < 2.6 km/s velocity resolution) Very Large Array (VLA) HI survey for 41 nearby dwarf galaxies in the local group within 10 Mpc. The rotation curves derived using the high- resolution HI data in a homogeneous and consistent manner are combined with Spitzer 3.6μm and ancillary optical U, B, and V images to construct mass models of the galaxies. These high quality multi-wavelength dataset significantly reduce observational uncertainties, allowing us to examine the mass distribution in the
galaxies in detail. The derived dark matter distributions in the central region of the galaxies are well consistent with those of dwarf galaxies from ‗The HI Nearby Galaxy Survey‘ (THINGS), showing much shallower slopes of their mass density profiles in the inner parts. This is in contrast with classical dark-matter-only cosmological simulations, which predict cusp-like dark matter density profiles with steep inner slopes. The core-like dark matter distributions in the LITTLE THINGS dwarf galaxies are more in line with those found in ΛCDM Smoothed Particle Hydrodynamic (SPH) simulations in which the effect of baryonic feedback processes is included.
[B3C-4-4] 16:50~17:05
Cosmic Dust and Cosmology
Thomas Prevenslik (QED Radiations, Hong Kong)
Introduction Since Hubble, cosmology based on Doppler‘s redshift considers the Universe as finite beginning and expanding since the Big Bang. If, however, Hubble‘s redshift is shown to have a non-Doppler origin, the Universe need not be expanding. Redshift without an expanding Universe is of utmost importance as the outstanding problems in cosmology would be resolved. Purpose Redshift of galaxy light is shown to occur upon absorption in submicron cosmic dust NPs by the mechanism of QED induced radiation. NP stands for nanoparticle and QED stands for quantum electrodynamics. QED induced redshift treats the absorbed galaxy photon as EM energy confined by the cosmic dust NP under TIR confinement. EM stands for electromagnetic and TIR for total reflection. QED redshift is a consequence of QM that precludes the NP atoms under TIR to increase in temperature upon absorbing the galaxy photon. QM stands for quantum mechanics. Instead, the photon is redshift depending on the properties of the NP. Theory and Results The Galaxy photon having wavelength is induced by QED to create a redshift photon of wavelength o = 2 nd, where D and n are the diameter and refractive index of the cosmic dust particle. The redshift Z = ( o - ) / . For the Lyman- photon and silicate cosmic dust, the QED induced redshift Z and the recession velocity of the Galaxy to the speed of light V/c by Doppler‘s effect as shown.
Poster Session 17:05~17:30 Chairs: Tzu-Ching Chang (Academia Sinica Institute of Astronomy and Astrophysics)
Dharam (Vir) Lal (National Centre for Radio Astrophysics (NCRA-TIFR))
Session: [B3C-5] S5 : Compact Objects, High Energy and Particle Astrophysics Date: August 20, 2014 (Wednesday) Time: 16:00~17:30 Room: Room E (Room 107) Chair: Gavin Rowell (University of Adelaide)
[B3C-5-1] 16:00~16:15
The Interaction of Microquasar Jets with a Stellar Wind in High-Mass X-ray Binaries
DooSoo Yoon (University of Wisconsin-Madison, USA) and Sebastian Heinz
Jets powered by high-mass X-ray binaries must traverse the powerful wind from the companion star. We present the first 3D simulations of jet-wind interactions in high-mass X-ray binaries. We show that the wind momentum flux intercepted by the jet can lead to significant bending of the jet. We show that jets propagating through a spherical wind will be bent to an asymptotic angle ψ∞ that differs from the cumulative angle of 180◦ expected for jets propagating through uniform wind, and derive simple expressions for ψ∞ as a function of jet power and wind thrust. The orbital motion of the binary must therefore lead to jet precession on the orbital period, with an opening angle of ψ∞. For known wind parameters, measurements of ψ∞ can be used to constrain the jet power. In the case of Cygnus X-1, the lack of jet precession as a function of orbital phase observed by the VLBA can be used to put a lower limit of Pjet ≥ 2 x 1036 ergs s-1 (α/2°)2 (vjet/0.1c) for reasonable estimates of the wind flux from the O9.7 Iab companion, where α is the half-opening angle of the jet and vjet is the jet velocity. We further discuss the case where the initial jet is inclined relative to the binary orbital axis. We also analyse the case of Cygnus X-3 and show that jet bending is likely negligible unless the jet is significantly less powerful than currently thought.
[B3C-5-2] 16:15~16:30
The Effect of X-ray Irradiation on the Time Dependent Behavior of Accretion Disks with Stochastic Perturbations
Bari Maqbool (University of Kashmir, India), Ranjeev Misra, and Naseer Iqbal
The UV emission from X-ray binaries, may arise from the outer accretion disk. The structure of the outer disk may be altered due to the presence of X-ray irradiation and we discuss the physical regimes where this may occur and point out certain X-ray binaries where this effect may be important. The long term X-ray variability of these sources is believed to be due stochastic fluctuations in the outer disk, which propagate inwards giving rise to accretion rate variation in the X-ray producing inner regions. Our motivation is to understand the effect of X-ray irradiation in such a scenario. To this end, a time dependent hydrodynamical framework with X- ray irradiation needs to be set up, such that the effect of fluctuations in the outer disk can be studied. We started, following earlier works, to solve for the steady state accretion disk structure taking into account irradiation. To understand the qualitative behavior, we adopt simplistic assumptions that the disk is fully ionized and it is not warped. We then proceed to develop a time dependent hydrodynamic code, which in the absence of perturbations is numerically stable. A sinusoidal perturbation was introduced at different radii, and its effect on the mass accretion rate in the inner disk was computed. The code was carefully studied to verify that the results are invariant to the numerical time steps and radial bins used. While we didn‘t find any oscillatory or limit cycle behavior due to the X-ray irradiation feedback, our results show irradiation enhances the X-ray variability at time-scales corresponding to the viscous time-scales of the irradiated disk.
[B3C-5-3] 16:30~16:45
Quantum Interference Effects in Spacetime of Slowly Rotating Compact Objects in Conformal Weyl Gravity
Abdullo Hakimov (Ulugh Beg Astronomical Institute, Uzbekistan)
General relativistic quantum interference effects in the fourth-order theory of slowly rotating conformal Weyl space-time as the phase shift effect and the Sagnac effect of interfering particle in neutron interferometer are considered. Using the covariant Klein-Gordon equation in the nonrelativistic approximation, it is shown that the phase shift in the interference of particles includes the additional potential terms with the weyl parameter. This term can be, in principle, detected by sensitive interferometer and derived results can be further used in experiments to detect the hidden mass which is responsible for the galactic rotation curve. It was found that in the case of the Sagnac effect the influence of weyl parameter is becoming important due to the fact that the angular velocity of the locally non rotating observer must be smaller than one in the Kerr space-time. Here we study quantum interference effects in particular the phase shift effect in a neutron interferometer and Sagnac effect in conformal Weyl gravity model. It has been shown that the static, spherically symmetric fourth-order conformal Weyl spacetime was converted into the rotational one by using the Newman-Janis algorithm. We have studied quantum interference effects including e.g. the phase shift and time delay in Sagnac effect in the spacetime of rotating gravitational objects conformal fourth-order Weyl gravitational theory and found that they can be affected by the integration constant of the theory which is responsible for the dark matter in galaxies. Then, we have derived an additional term for the phase shift in a neutron interferometer due to the presence of linear term in slowly rotating metric and studied the feasibility of its detection with the help of interferometer. Here we have estimated lower limit for parameter as using the experimental results on the precise measurement of the gravitational redshift by the interference of matter waves.
[B3C-5-4] 16:45~17:00
Multi-Observation Identification for Studying the Evolution of Spin-Up Line
Ali Taani (Al-Balqa' Applied University, Jordan)
Observation and analysis of pulsars has proven to be a valuable tool in the comprehension of their nature and physics. These classes of gorgeous objects are extremely important as a test-bed for understanding the magnetic field which consider among the enigmatic issues (see e.g., Bhattacharya & van den Heuvel 1991 for an extended review, Stairs 2004 and Lorimer 2008). Hence the magnetic field strengths at the Neutron Star (NS) surface, derived assuming dipole fields, differ by four orders of magnitude between Millisecond Pulsars (MSPs) and young pulsars. The increased number of objects improves the statistics for some parameters such as spin period and magnetic field, thus helping to: refine existing models, provide an update distribution to the wide variety and natures of population, discuss the various formation scenarios and provide us with constraints that help us improve our understanding of binary evolution. This is the aims of the present paper. To quantitatively describe the evolution and formation of pulsars population diagram, I perform a statistical study that combined different natures of binaries with a compact component, such as, normal pulsars, MSPs, Fermi pulsars, Supernova Remanents (SNRs) Magnetars and High-Mass X-Ray Binaries (HMXBs) that observed in different energy bands. In addition I fit the surface magnetic field and spin period distribution function (so called spin-up line or B - P diagram) of observed sample. I find that pulsars that have evolved through different evolutionary paths reflect distinctive signatures through dissimilar distribution of magnetic field and spin period values during the spin-up phase. The implications of the results are to provide constraints on binary evolution and characteristics of the binary pulsar population. Furthermore, in a steady state there should be a constant flow of pulsars in the B-P diagram from the region where they are born to the region where they die.
Poster Session 17:00~17:30 Chairs: Gavin Rowell (University of Adelaide) Maurice van Putten (Sejong University)
Session: [B3C-6] S6 : Observing Facilities and International Collaborations Date: August 20, 2014 (Wednesday) Time: 16:00~17:30 Room: Room F (Room 108) Chair: Jongsoo Kim (Korea Astronomy and Space Science Institute)
[B3C-6-1] 16:00~16:15
[Invited] Key Science Observations of AGNs with KaVA Array
Motoki Kino (Korea Astronomy and Space Science Institute, Korea)
I will introduce early science results of AGN observations with KaVA which is the combined array of the Korean VLBI network (KVN) and VLBI Exploration of Radio Astrometry (VERA).Then, I will present our future plan of monitoring observation of Sgr A* and M87. Because of the largeness of their central super-massive black holes, we select them as top priority sources of our key science program (KSP). The main science goals of the KSP are (1) mapping the velocity field of the M87 jet and testing magnetically-driven-jet paradigm, and (2) obtaining tightest constraints on physical properties of radio emitting region in Sgr A*.
[B3C-6-2] 16:15~16:30
[Invited] Planning Large Programs of Stellar Maser Studies with KaVA
Se-Hyung Cho (Korea Astronomy and Space Science Institute, Korea), Hiroshi Imai, and the KaVA Evolved Star sub-Working Group
We will present our activities to plan out large programs for studying circumstellar H2O and SiO maser sources with KaVA (combined network of Korean VLBI Network: KVN and Japanese VLBI Exploration of Radio Astrometry: VERA). A great advantage of KaVA for the stellar maser observations is the combination of unique capability of the multi-frequency phase referencing technique and the dual-beam astrometry using KVN and VERA, respectively. We have demonstrated this advantage through the test observations conducted by the KaVA Evolved Star Sub-working Group from 2012 March to 2014 March. Snapshot imaging with KaVA is confirmed to be possible in integration time of 0.5 hour at 22 GHz band and 1.0 hour at 43 GHz band in typical cases. This implies that large snapshot imaging surveys towards many H2O and SiO stellar masers are possible within a reasonable machine time (e.g., scans on ~100 maser sources within ~200 hours). Therefore, we selected about 100 candidate target sources which are suitable for future long-term (~10 years) intensive (biweekly-monthly) monitoring observations, based on KVN K/Q-band single-dish observational results toward about 1000 evolved stars. The output of the snapshot imaging program will be used for statistical analyses of the structures of individual maser clumps and the spatio-kinematical structures of circumstellar envelopes undergoing accelerating outflows. The combination of astrometry in milliarcsecond(mas) level and the multi-phase referencing technique enables us to measure not only trigonometric parallax distances of masers but also precise reference position for registration of different maser lines. The accuracy of the map registration affects an interpretation of the excitation mechanism of SiO maser lines and the origin of various maser actions, which are expected to reflect periodic behaviors of the circumstellar envelope with stellar pulsation. Currently we are checking the technical feasibility of KaVA operation for this combination. After the feasibility test and further careful selection of about 20 sources, the long-term monitoring campaign program will be propelled as one of KaVA legacy projects.
[B3C-6-3] 16:30~16:45
[Invited] Observational Studies of Star-forming Regions with KVN and KVN+VERA
Kee-Tae Kim (Korea Astronomy and Space Science Institute, Korea), Tomoya Hirota, and KVN+VERA Star Formation Working Group
Methanol masers are divided into two classes, class I and class II. Class II methanol masers trace the disk- outflow systems of massive young stellar objects (YSOs), while class I methanol masers appear to trace the interaction regions of outflows with the ambient molecular gas. Class II masers have been extensively studied by single dishes, connected arrays, and VLBIs. Meanwhile, class I masers have been much less studied. They have not been detected by any VLBI facility. Thus they have been believed to have more extended structures than class II masers. We made fringe surveys of 44GHz class I methanol maser emission towards about 170 massive YSOs with flux densities >10 Jy using KVN, and detected fringes in ~20% of the sources. This is the first VLBI detection of class I methanol masers. We performed follow-up imaging observations of the detected maser sources with KVN and KVN+VERA. The observations aim to investigate the distribution and kinematics of 44GHz methanol maser features in each source at milli-arcsecond resolutions, and to understand what they trace. In this talk we will present the fringe survey and imaging results, and discuss the implications.
[B3C-6-4] 16:45~17:00
[Invited] The Shanghai 65m Radio Telescope
Zhi-Qiang Shen (Shanghai Astronomical Observatory, China) and the Shanghai 65m Radio Telescope Project Team
The Shanghai 65m radio telescope is a general purpose, fully steerable radio telescope. It features a shaped Cassegrain antenna comprised of a 65-meter diameter main reflector with a primary focal ratio of 0.32 and a 6.5-meter diameter sub-reflector. The main reflector is made up of 14 rings of 1008 high-precision solid panels, each having an area of 2.66-4.90 square meters. The sub-reflector is comprised of 3 rings of 25 aluminum honeycomb sandwich panels. The accuracies of the panels in the primary and sub-reflectors are better than 0.1 mm (rms) and 0.05 mm (rms), respectively. A novel technology known as active surface control scheme was adopted for assembling the main reflector. A total of 1104 actuators were installed at the locations where the panels join the antenna backup structure so as to compensate for gravity deformation in the reflecting surface during tracking. This can greatly improve the observing efficiency at high frequencies. The whole supporting track employed seamless welding technique, by which 30 precision-machined 6-ton segments were all-welded together to be a single track with an overall unevenness of 0.5 mm (rms). This technique has laid the foundation for assuring the precision of the antenna‘s axial system. The telescope is fitted with receiving equipment for eight frequency bands (namely L, S, C, X, Ku, K, Ka and, Q) corresponding to an observing wavelength coverage from 7 mm to 21 cm. The frequency switch can be accomplished within one minute. The Shanghai 65m radio telescope saw its first light on October 26, 2012, when a trial run was successfully launched at a wavelength of 18 cm towards a massive star forming region. On November 28, 2012, fringes were successfully detected on a single baseline to the 25-meter VLBI station at Sheshan, Shanghai. Relying on its superiorities such as better sensitivity and wider frequency coverage, the Shanghai 65m radio telescope will play an extremely important role in the astronomical observations of molecular spectral line emission and pulsar. When used in the single-dish mode, the telescope will also perform observation of various radio sources, with specific targets including radio-loud blazars, micro-quasars and X-ray binaries. Research activities on the fast time variation of Active Galactic Nuclei and the transient phenomenon of X-ray binaries are key topics for high-sensitivity single-dish observations. As a key element of the VLBI network in China and the world, it significantly increases its sensitivity for VLBI observations. This is China‘s first radio telescope capable of observing at the 7 mm wavelength, and then will open up new areas of millimeter wave VLBI observations.
Poster Session 17:00~17:30 Chairs: Jongsoo Kim (Korea Astronomy and Space Science Institute) Hideyuki Kobayashi (National Astronomical Observatory of Japan)
Session: [B4A-2] S2 : Interstellar Matter, Star Formation and the Milky Way Date: August 21, 2014 (Thursday) Time: 11:00~12:30 Room: Room B (Room 103) Chair: Jeong-Eun Lee (Kyung Hee University)
[B4A-2-1] 11:00~11:20
[Invited] Organic Dust in the Interstellar Medium
Sun Kwok (The University of Hong Kong, Hong Kong, China)
Tradition view of dust in the interstellar medium is that they are made of graphite and silicates. In this talk, we discuss the evidence for complex organics being a major component of interstellar dust. Comparison between astronomical infrared spectra and laboratory spectra of amorphous carbonaceous materials suggests that organics of mixed aromatic-aliphatic structures are widely present in circumstellar, interstellar, and galactic environments. Scenarios for the synthesis of these compounds in the late stages of stellar evolution will be presented. We will also explore the relationship between interstellar organic dust and complex organics found in the Solar System.
[B4A-2-2] 11:20~11:40
[Invited] Infrared Properties of Interstellar Dust Grains
Hidehiro Kaneda (Nagoya University, Japan), Daisuke Ishihara, Toru Kondo, Shinki Oyabu, Rika Yamada, Mitsuyoshi Yamagishi, Takashi Onaka, and Toyoaki Suzuki
In star-forming regions, dust and polycyclic aromatic hydrocarbons (PAHs) absorb a significant fraction of stellar ultraviolet (UV) photons and re-radiate them in the infrared (IR). Hence the IR luminosities due to dust and PAH emission are both powerful tools to trace star-forming activities in galaxies. However they are not merely tracers of star-formation activity. Spectral information on the dust and PAH emission would have much deeper physical implications for understanding the properties of the ISM. In this context, our Galaxy provides ideal laboratories for detailed studies of dust in particular conditions, while nearby galaxies provide us with a much wider range of the ISM physical conditions than our Galaxy. With AKARI, we have performed a systematic study of interstellar dust grains in various environments of our Galaxy and nearby galaxies. Because of its unique capabilities, such as near- and far-IR spectroscopy combined with all-sky coverage in the mid- and far-IR, AKARI has provided new knowledge on the processing of dust, particularly carbonaceous grains including PAHs, in the interstellar space. The AKARI mid-IR all-sky diffuse map for the first time reveals that PAHs are widely and almost ubiquitously distributed along the Galactic plane. Near the Galactic center, we find a dust feature likely due to large graphite grains in the AKARI far-IR spectra taken from a cloud located near Sgr A*, which may indicate the past activity of the Galactic center. For nearby galaxies, we find that copious amounts of large grains and PAHs are flowing out of starburst galaxies by galactic superwinds, which are being shattered and destroyed in galactic haloes. AKARI near-IR spectroscopy has revealed spatial variations in the ratio of the aromatic to the aliphatic hydrocarbon spectral feature in galaxies, indicating structural changes of carbonaceous grains possibly due to large-scale shocks. AKARI also detects near-IR absorption features due to interstellar icy grains from many nearby galaxies, providing unique tools to probe the chemical evolution of the ISM. In this talk, we review the results obtained from our AKARI observations on the processing of interstellar dust grains in various harsh environments of our Galaxy and nearby galaxies, together with some results from Spitzer and Herschel observations. We also refer to our future prospect for this topic with SPICA, which is scheduled to be launched in the mid 2020‘s.
[B4A-2-3] 11:40~12:00
[Invited] Microwave Emission from Spinning Dust: An Improved Model and Polarization Spectrum
Thiem Hoang (Ruhr University Bochum, Germany)
Planck results have reinforced that the electric dipole emission from rapidly spinning polycyclic aromatic hydrocarbons (PAHs) is a reliable explanation for the anomalous microwave emission that interferes with cosmic microwave background (CMB) radiation experiments. The emerging question is to what extent this emission component contaminates to the polarized CMB radiation. I will first present an improved model of spinning dust emission, which considers realistic dynamics of wobbling non-spherical grains and their impulsive interactions with ions in the ambient plasma. I will then discuss recent progress in predicting the alignment of small grains and present theoretically expected degree of polarization of spinning dust emission. Finally, I will present new constraints on the degree of polarization of spinning dust emission and polarization spectrum, which are obtained using inversion technique combined with theoretical calculations. The new results would be useful for interpreting incoming CMB polarization data from Planck and numerous CMB missions in the microwave frequency range.
[B4A-2-4] 12:00~12:15
Mapping the 3D Multi-Band Extinction and Diffuse Interstellar Bands in the Milky Way with LAMOST
Haibo Yuan (Peking University, China), Xiaowei Liu, Maosheng Xiang, Yang Huang, and Bingqiu Chen
Constructing a 3D Galactic extinction map plays an essential role in Galactic astronomy, particularly in achieving the driving goals of the LAMOST Galactic Surveys. The nature and origins of diffuse interstellar bands (DIBs) are one of the most challenging problems in astronomical spectroscopy. With the modern large scale spectroscopic surveys, such as SDSS andLAMOST, Galactic astronomy is entering into an era of millions of stellar spectra. Taking advantage of such huge spectral database, we proposed a) Using the "standard pair" technique to measure extinction (accurate to 0.01-0.03 mag) of a large sample of individual stars (Yuan, Liu & Xiang 2013) and b) Using the "template subtraction" technique to detect and measure DIBs in the SDSS and LAMOST low-resolution spectra (Yuan & Liu, 2012). Both methods can apply to most stellar types and are independent on the systematic errors of stellar parameters. In this contribution, we will report the results on mapping the 3D Galactic extinction maps, extinction law from Far-UV to mid-IR and its variations, and DIBs with about one million LAMOST spectra.
Poster Session 12:15~12:30 Chair: Jeong-Eun Lee (Kyung Hee University)
Session: [B4A-3] S3 : Stars, Exoplanets and Stellar Systems Date: August 21, 2014 (Thursday) Time: 11:00~12:30 Room: Room C (Room 104) Chair: Daniel Bayliss (Australian National University)
[B4A-3-1] 11:00~11:20
[Invited] High Time Resolution Astrophysics: New Results from the Thai 2.4m Telescope with ULTRASPEC
Puji Irawati (National Astronomical Research Institute of Thailand, Thailand), Andrea Richichi, Vik Dhillon, Thomas R. Marsh, Agnieszka Slowikowska, and Boonrucksar Soonthornthum
The recently inaugurated Thai National Observatory (TNO) is equipped with a 2.4m Ritchey-Chretien telescope and the high-speed versatile ULTRASPEC camera. This new facility is located at 2457m elevation on Doi Inthanon, 100 km from the city of Chiang Mai. ULTRASPEC is a visitor instrument, built by a Consortium of UK institutes, which will be available at TNO initially until mid 2015, and possibly for longer. This instrument employs a low-noise, frame-transfer EMCCD designed for observation of faint objects and for high time resolution astrophysics. We present some of the results obtained in the first observing cycle (November 2013 – April 2014), focusing particularly on fast photometry data. A highly flexible scheme of sub- array readout allows us to reach a time resolution as fast as 400Hz. This method is suitable to follow fast phenomena such as lunar occultations. The seconds to sub-second resolution is ideal to observe the brightness variability in close binaries (flickering and Light Travel Time) or transit of exoplanets, while longer exposures offer a superb image quality over the 300-1000nm range. We also outline the opportunities for observations in Cycle 2, for which proposals are due in summer 2014.
[B4A-3-2] 11:20~11:35
Searching for and Characterization of Galactic Open Clusters
Wen-Ping Chen (National Central University, Taiwan) and Chien-Cheng Lin
Stars are formed in groups out of molecular clouds. Star clusters serve as laboratories to test stellar evolutionary models, and to study dynamical interactions among member stars, and with Galactic environments. While some hundreds of thousand open clusters are expected on the Galactic disk, so far only a few thousands have been catalogued, all in the solar neighborhood, with a fraction of which are characterized with cluster parameters and member lists. The incompleteness of the open cluster sample is largely due to the extinction in the disk and also due to the lack of systematic search in sky surveys covering sufficient volume in space. Here we report on a pilot program to identify stellar density enhancements toward the Galactic anti-center using the Pan-STARRS 1 data. An analysis pipeline has been devised to find a cluster candidate, and derive its size, shape, number of members, distance, age, and reddening. We report the methodology, showcase a few candidate clusters that we found, and present how our study improves significantly the Galactic open cluster sample.
[B4A-3-3] 11:35~11:50
Relative Age Measurements of the Metal-Poor Globular Clusters M53 and M92
Dong-Hwan Cho (Kyungpook National University, Korea), Hyun-Il Sung, Sang-Gak Lee, and Tae Seog Yoon
CCD photometric observations of the globular cluster (GC), M53 (NGC 5024), were performed using the 1.8 m telescope at the Bohyun Optical Astronomy Observatory on the same nights (April 2002 and May 2003) as the observations of the GC M92 (NGC 6341) reported by Cho and Lee using the same instrumental setup.
The data for M53 was reduced using the same method for reducing the data for M92 by Cho and Lee, including preprocessing, point-spread function fitting photometry, and standardization etc. to provide accurate relative age measurements of GCs M53 and M92. Therefore, GCs M53 and M92 were on the same photometric system defined by Landolt, and the photometry of GCs M53 and M92 was tied together as closely as possible. After the complete photometric reduction steps, the V versus B-V, V versus V-I, and V versus B-I color-magnitude diagrams (CMDs) of GC M53 were produced to derive the accurate relative ages of the GCs M53 and M92 and derive the various characteristics of the CMDs of M53 in future analysis. From the present analysis, the relative ages of GCs M53 and M92 were derived using the Δ(B-V) method reported by VandenBerg et al. The relative age of GC M53 was found to be 1.6 ± 0.85 Gyr younger than that of GC M92 if the absolute age of M92 is taken to be 14 Gyr. This relative age difference between GCs M53 and M92 caused slight differences in the horizontal-branch morphology of these two GCs. In addition, the confirmation of the results of the present analysis is being tried with the accurate and homogeneous VI photometric data of the GCs M53 and M92 by the ACS/WFC aboard the Hubble Space Telescope.
[B4A-3-4] 11:50~12:05
Characterization of Faint Photometric and Kinematic Members in the Open Cluster NGC752
Chung-Kai Huang (National Central University, Taiwan), Chien-Cheng Lin, Pei-Yi Chen, A-Li Luo, and Wen- Ping Chen
Open Clusters play an important role in studying stellar evolution, as well as the formation and evolution of the Galactic disk. Identification of member stars in a star cluster is the first step to derive the fundamental physical parameters of the cluster, such as the distance, age, size, spatial distribution, reddening, and metallicity. As a pilot program to identify and study low-mass members in open clusters, perhaps extending to substellar objects in nearby clusters, we present the analysis of NGC752 by using the PPMXL proper motion and Pan-STARRS photometric data to characterize the members near the hydrogen burning stellar masses. Some bright stars have been measured radial velocities by the LAMOST, rendering further constraints on membership determination. The secure member list allows us to quantify the dynamical evolutionary history such as mass segregation and stellar evaporation of the cluster.
Poster Session 12:05~12:30 Chair: Daniel Bayliss (Australian National University)
Session: [B4A-4] S4 : Galaxies, AGN and Cosmology Date: August 21, 2014 (Thursday) Time: 11:00~12:30 Room: Room D (Room 105~106) Chair: Grant J. Mathews (University of Notre Dame)
[B4A-4-1] 11:00~11:20
[Invited] Application of Cepheids in Distance Scale: Extending to Ultra-Long Period Cepheids
Chow-Choong Ngeow (National Central University, Taiwan)
Classical Cepheids (hereafter Cepheids) belong to a class of important variable stars that can be used to determine distance to nearby galaxies via the famous period-luminosity (P-L) relations, i.e. the Leavitt Law. In turn, these distances can then be used to calibrate a host of secondary distance indicators that located well within the Hubble flow, and ultimately determine the Hubble constant independent of the CMB measurements with WMAP and/or Planck. In this talk, I first review recent work on the calibration of the Cepheids P-L relations, followed by summarizing some recent progress in determining the Hubble constant to within ~3% level via the cosmic distance scale ladder. In second part of the talk, I will discuss the prospect of using ultra- long period Cepheids (ULPC) in future distance scale work. ULPC are those Cepheids with periods longer than 80 days, and seems to follow a different P-L relation than their shorter period counterparts. About 30 ULPCs have been identified in Magellanic Clouds, nearby dwarf galaxies and spiral galaxies. It has been suggested that ULPC can be used to determine the Hubble constant in "one-step". Analysis of the properties of this ULPC sample will be summarized.
[B4A-4-2] 11:20~11:35
Variability of Broad Absorption Lines in a QSO SDSS on Multi-year Timescales
Weihao Bian (Nanjing Normal University, China) and Zhicheng He
The variability of a BAL QSO at z = 2.719 is investigated, with 18 SDSS/BOSS spectra covering 4128 days in the observed frame. With the ratio of the rms spectrum to the mean spectrum, the relative flux change of the BAL-trough is larger than that of the emission lines and the continuum. We calculate the EW for different epochs, as well as the continuum luminosity and the spectral index. It is found that there is a strong correlation between the BAL-trough EW and the spectral index, and a weak negative correlation between the BAL-trough EW and the continuum luminosity, suggesting that dust is intrinsic to outflows and the BAL-trough variation is not dominated by photoionization.
[B4A-4-3] 11:35~11:50
On The Long Time Spectral Variability Of NGC 5548
N. Z. Ismailov (Shamakhy Astrophysical Observatory Azerbaijan of NAS, Azerbaijan) and U. Z. Bashirova
We have investigated a long time variability of intensities of the broad-line region emission lines in the UV spectrums of Seyfert I galaxy NGC 5548 for 1973-1996. The spectral material we were taken from IUE archive. A spectral range is λ1000-3000 Å Å and a spectral resolution is at 6 Å . In this report we have presented results of researches the time variability of spectral line intensities for SiIV/OIV 1400, CIV 1550, HeII1640, CIII] 1909 and MgII 2800. Moreover we have controlled flux variations in the continuum for the 6 wavelength in this spectral range. In this study we have got following results: 1)a high level correlation between intensities of emission lines as well as between intensities of emission lines and continuum fluxes was discovered. With increasing of wavelength a correlation in both cases are standing weaker, 2)the relationship between the intensity of emission lines and the flux radiation in the continuum can be expressed by the power function with power coefficient α~0.8-1.1 for different lines. When the difference between
wavelengths of spectral lines and continuum is increases, the power coefficient is decreased, 3)it was found that the amplitude of variability of the line intensities is weaker than the continuum flux amplitude of variability. The amplitude of variability both in the intensities of lines and in the continuum flux radiation are increased for the longer wavelength range.
[B4A-4-4] 11:50~12:05
Dynamics of Elliptical Galaxies in the Framework of MOdified Newtonian Dynamics
Chung-Ming Ko (National Central University, Taiwan) and Yong Tian
Planetary nebula in elliptical galaxies posed a problem in dark matter theory. Using data from Planetary Nebula Spectrograph (PN. S), Romanowsky et al. (2003) reported that less than expected dark matter were found in three elliptical galaxies. We revisit this problem using MOdified Newtonian Dynamics (MOND), an alternative to dark matter paradigm. We collect 22 elliptical galaxies with planetary nebulae from the PN. S. We adopt Hernquist model for the elliptical galaxies and find that MOND explains the observations well. We also compare the results with the ones from Newtonian dynamics.
Poster Session 12:05~12:30 Chair: Grant J. Mathews (University of Notre Dame)
Session: [B4A-5] S7 : Historical Astronomy, Astronomy Education and Public Outreach Date: August 21, 2014 (Thursday) Time: 11:00~12:30 Room: Room E (Room 107) Chair: Tsolmon Renchin (National University of Mongolia)
[B4A-5-1] 11:00~11:15
[Invited] Astronomy as a Part of Culture
Hidehiko Agata (National Astronomical Observatory of Japan, Japan)
What is ―science communication‖? There are still no consensus among all the people. In 2009, the scientists attended the World Conference of Science held at Budapest had agreed on and published the Budapest Declaration.21st century science served 4 major responsibilities - "Science for knowledge "," Science for Peace ","Science for development " and "Science for Society and Science in Society". By extending the idea of Stocklmayer1), I propose the science communication as follows. Science communication is a process that the knowledge and culture of science is absorbed into the culture of the larger community, in return it feedback to science itself, it is a process that will affect the individual and society as a whole. [Context of society]: In modern society, the society has required each citizen to be educated on the nature of science, furthermore, modern society has required each citizen to act proactively the challenges facing society. [Context of individual]: On the other hand, science is not only for bringing economic development and convenience, science is also a kind of culture to make lives more mentally rich. Exploration of science, including astronomy, is the result of intellectual curiosity of the human from the old days. Astronomy should be respected as cultural activities in the same way as art, literature and sport. There are many cultural activities that provide leisure for the citizens. Will astronomy be able to contribute to the list and give happiness to the people? In order to realize this idea, we have started making a science instruction network from various Japanese places. "Astronomy as a part of culture" are demonstrated through science festivals, science cafes, science shows, and star watching parties that are being carried out in Japan. In this talk, we discuss how is the role of astronomy that represents science in culture. 1) S. Stocklmayer, M.M. Gore and C. Bryant (eds.): Science Communication in Theory and Practice (Dordrecht, Amsterdam, 2001).
[B4A-5-2] 11:15~11:30
[Invited] The Creative Approach for Disseminating Astronomy to the General Public
Yudhiakto Pramudya (Universitas Ahmad Dahlan, Indonesia) and Widya Sawitar
The astronomical outreach activities for the general public that are unfamiliar to astronomy is challenging task. It requires creative thinking to solve the problems. The amateur astronomical club in a number of cities in Indonesia have routine schedule for observation at public parks. The interaction between those clubs and formal education institution is established by face to face interaction and assisted by social media. The physics teachers who took astronomy course in the university are potential resources to enlarge the outreach scope by creating astronomical club as an extracurricular activities. Recent progressive trend in astronomy dissemination for the disabled is also great opportunity to asisst the disabled for experiencing hands-on activities based on formal and informal education.
[B4A-5-3] 11:30~11:45
[Invited] Stars of Asia
Fumi Yoshida (National Astronomical Observatory of Japan, Japan), Norio Kaifu, and Working group of Stars of Asia
The Stars of Asia project was one of the IYA 2009 activities. The aim of the project is to collect the best Asian myths and legends relating to stars and the universe through the collaboration of Asian countries/regions and then publish attractive books about these stories in each country/region in local language, so that many people enjoy these stories at schools, planetarium, and home. In order to collect myths and legends from each country/region, we held a workshop, titled ―Star of Asia Workshop‖ at NAOJ, Tokyo, Japan, on 11-13 May 2009. Fifty people from 11 countries/regions attended the workshop and brought about 50 myths and legends originating from 14 countries/regions of Asia: Bangladesh, China, India, Indonesia, Japan, Korea, Malaysia, Mongolia, Nepal, Taiwan, Thailand, the Pacific Ocean, Vietnam. At the end of the workshop, the international editorial board was organized to edit the stories comprising ―Stars of Asia‖. The board consists of representatives from each country/region: Dulmaa Altangerel (Mongolia), Sze-leung Cheung (China), Yong Bok Lee (Korea), Norio Kaifu (Japan Chair), Quynh Ngoc Loung (Vietnam), Leena Damle (India), Jayanta Achrya (Nepal), F. R. Sarker (Bangladesh), Siramas Komonjinda (Thailand), Noriah Mohamed (Mylasia), Widya Sawitar (Indonesia), Akira Goto (The Pacific Ocean), and Yi-Nan Chin (Taiwan). The Editorial Board members selected myths and legends and prepared original illustrations and pictures representing culture of each country/region for decorating stories. We planned to edit an English version of Book ―Stars of Asia‖ first, then translate to local language of each country/region because only English is available as a common language in Asian region. However, we have noticed that publishing English book in Asian country is not easy, because Asian publishers do not have market of English books. Therefore we decided to compile with Japanese first and then make the English book with the help of Univ. of Hawaii Press. The Japanese version of Book ―Stars of Asia‖ was finally published on 25 Feb. 2014. The book contains 68 myths and legends from 13 countries/regions of Asia. The stories are distributed into two parts: the Part1 and the Part2. The Part1 includes most popular stories in each country/region. In the Part2, stories are classified with celestial objects. There are many different stories on bright objects: Sun, Moon, planets, remarkable star group and constellation (e.g. the Big Dipper, Orion etc.). This book contains a lot of colorful illustrations gathered from all over the Asian area. Through these colorful illustrations, people will be able to experience the culture and history of various parts of Asia. Various stories appear from each religion, climate, and geographical area. In addition, stories exist that are common across Asia, like the story of Vega and Altair or the stories in Rahu. These seem to have been disseminated by the racial migration and religious and cultural propagation. We added a commentary part at the last part of the book. In there, outlooks of the universe in ancient Asia and a flow of myths and legends in East Asia region (including the Pacific ocean) are described for teachers and lecturers by several specialists: Prof. Mayank N. Vahia, Prof. Xiaochun Sun, and Prof. Akira Goto. The ―Stars of Asia‖ project is the first effort to collect myths and legends on stars and universe from broad area of Asia. We are sure that adults and children can both enjoy this book with beautiful illustrations and attractive stories. And those with an interest in folklore and ethnology will also enjoy this book. At the APRIM, we will introduce the book and prospect of the Stars of Asia project.
[B4A-5-4] 11:45~12:05
[Invited] International Year of Light 2015, Public Naming of Exoplanets and IAU Office for Astronomy Outreach
Sze Leung Cheung (IAU Office for Astronomy Outreach, Japan)
The International Astronomical Union (IAU) Office for Astronomy Outreach (OAO) is an IAU new office hosted at National Astronomical Observatory of Japan (NAOJ) at Tokyo. After the International Year of Astronomy 2009, IAU decided to establish the OAO to coordinate the international astronomical outreach efforts. Two major campaigns that OAO are running are the International Year of Light 2015 and the Public Naming of Exoplanets. IAU is one of the supporting organization of the International Year of Light 2015 (IYL2015), and one of the IYL2015 cornerstone project is ―Cosmic Light‖, which connect astronomy to light. OAO is the central hub of coordination for the Cosmic Light cornerstone. On the other hand, IAU has also launched the NameExoWorlds campaign, inviting public to name exoplanets, using a different approach than the naming of solar system bodies like asteroids or comets, the naming of exoplanetary system will involve public voting and proposal nominations from public organizations.
Poster Session 12:05~12:30 Chair: Tsolmon Renchin (National University of Mongolia)
Session: [B4A-6] S6 : Observing Facilities and International Collaborations Date: August 21, 2014 (Thursday) Time: 11:00~12:30 Room: Room F (Room 108) Chair: Hyung Mok Lee (Seoul National University)
[B4A-6-1] 11:00~11:20
[Invited] The KAGRA Project
Takaaki Kajita (University of Tokyo, Japan)
KAGRA is a large-scale cryogenic gravitational wave detector, which is under construction in Kamioka, Japan. The status and plan of the KAGRA project will be discussed
[B4A-6-2] 11:20~11:40
[Invited] LiteBIRD - CMB Polarization Mission for Detecting Primordial Gravitation Wave
Masashi Hazumi (High Energy Accelerator Research Organization, Japan)
LiteBIRD is a satellite to map the polarization of the cosmic microwave background (CMB) radiation over the full sky at large angular scales with ultimate precision. Cosmological inflation, which is the leading hypothesis to resolve the problems in the Big Bang theory, predicts that primordial gravitational waves were created during the inflationary era. Measurements of polarization of the CMB radiation are known as the best probe to detect the primordial gravitational waves. The LiteBIRD working group is authorized by the Japanese Steering Committee for Space Science (SCSS) and is supported by JAXA. It has more than 60 members from Japan, USA, Canada and Germany. Studies in the working group are in progress toward the mission definition review, with a target launch year in early 2020‘s. The scientific objective of LiteBIRD is to test all the representative inflation models that satisfy single-field slow-roll conditions and lie in the large-field regime. To this end, the requirement on the precision of the tensor-to-scalar ratio, r, at LiteBIRD is equal to or less than 0.001. In case of large r values, as suggested by BICEP2, LiteBIRD will be able to scrutinize the power spectrum of the B-mode polarization to further narrow-down inflationary models. The design of the LiteBIRD system is driven by these scientific goals. A 3-year full sky survey will be carried out for 6 frequency bands between 50 and 320 GHz to achieve the total sensitivity of 1.8 microKarcmin with the angular resolution of 30 arcmin at 150 GHz. The key components of the mission payload include a half-wave plate system for signal modulation, two reflective mirrors with a diameter of about 60 cm, an array of superconducting polarimeters read out with high multiplexing factors in the frequency domain, and the cryogenic system to provide the 100 mK base temperature
[B4A-6-3] 11:40~12:00
[Invited] Constraining the Binary Inclination Angle Using Multi-Detector GW Observations
Archana Pai (Indian Institute of Sience Education and Research, India )
Compact binary mergers are the strongest candidates for the progenitors of Short Gamma Ray Bursts (SGRBs) for the advanced GW detectors. If a gravitational wave (GW) signal from the compact binary merger is observed in association with a SGRB, such a synergy can help us understand many interesting aspects of these bursts. In this talk, we discuss the accuracies with which a world wide network of gravitational wave interferometers would measure the binary inclination angle (angle between the angular momentum axis of the binary and observer's line of sight). We compare the projected accuracies of GW detectors to measure the inclination angle of double neutron star and neutron star-black hole binaries for different astrophysical scenarios.
[B4A-6-4] 12:00~12:15
Towards Gravitational Wave Detection with the Parkes Pulsar Timing Array
George Hobbs (CSIRO Astronomy & Space Science, Australia)
The Parkes Pulsar Timing Array project has been ongoing since the year 2005. The main goal of this project is to make a direct detection of ultra-low frequency gravitational waves. In my talk I will describe the current status of our data sets. These data sets are obtained by observing 25 millisecond pulsars with the most modern instruments at the Parkes observatory. They are currently the most sensitive data sets available for searching for gravitational waves in the pulsar-timing band. Much of the data is publically available and I will explain how any astronomer can access and make use of the data. I will highlight our recent stringent constraint on existence of a background of gravitational waves and describe the astrophysical implications of this result. I will also describe searches for individual supermassive binary black hole systems that are expected to emit gravitational waves and will also describe searches for gravitational wave burst events with memory.2 I will discuss our plans for the future and describe when we expect to be able to make a direct detection of gravitational waves. I will place the project in context with other pulsar timing array projects on existing (such as the International Pulsar Timing Array) and future (with the FAST telescope and SKA) telescopes.
Poster Session 12:15~12:30 Chair: Hyung Mok Lee (Seoul National University)
Session: [B5A-1] S1 : Solar System and Sun-Earth Interactions Date: August 22, 2014 (Friday) Time: 09:00~10:25 Room: Room A (Room 101~102) Chair: Shuhrat Ehgamberdiev (Ulugh Beg Astronomical Institute)
[B5A-1-1] 09:00~09:20
[Invited] The Observations of Comet 67P/C-G from the Ground-Based Telescopes and from In-Situ Instruments of Rosetta Spacecraft
Zhong-Yi Lin (National Central University, Taiwan), Wing-Huen Ip, and OSIRIS Team
ESA‘s Rosetta spacecraft has awoken from its long hibernation in mid-January 2014 and now is the way on its destination, comet 67P/Churyumov-Gerasimenko. The spacecraft will follow the comet 67P/C-G as it comes back to the perihelion (2015), monitoring the activity and releasing a lander to study the surface in-situ. We will summarize the monitoring results from the ground-based telescopes during its last perihelion passage (2009) and present the last observations (2014) of comet C-G. In parallel, the last images and preliminary results of comet 67P/C-G in-situ from Rosetta spacecraft‘s instrument, OSIRIS‘ camera, will also be presented.
[B5A-1-2] 09:20~09:40
[Invited] Astrometry for Natural Satellites of Planets in China
Q. Y. Peng (Jinan University, China), A. Vienne, Q. F. Zhang, N. Wang, and Z. Li
Astrometric observation for natural satellites of some major planets has been regularly performed in China since the 1990s. These satellites are mainly involved with the major satellites of Jupiter, Saturn, Uranus and Neptune. Different telescopes with apertures from 30 ~ 240 cm have been used. The observed approaches are mainly CCD tangent plane astrometry as well as photometric astrometry for some mutual events appearing in the satellite systems of Jupiter and Saturn. Several novel observational and image-analytic techniques are successfully developed for improving the precision of observations. Many observations as much as several thousands have been published with quite good precision.
[B5A-1-3] 09:40~09:55
Non-LTE and LTE Emissions of the 3.3-micron Bands of CH4 in the Auroral Regions of Jupiter
Sang Joon Kim (Kyung Hee University, Korea)
We developed radiative transfer programs to simulate the auroral emissions of the V3, V3+V4-V4 and V2+V3-V2 bands of CH4 in the auroral regions of Jupiter. We investigated non-LTE (local thermodynamic equilibrium) and LTE processes in the auroral regions considering excitations by auroral particle precipitations as well as fluorescent excitations by sunlight. We will discuss the magnitudes of the auroral excitations vs fluorescent excitations based on available high-altitude mixing ratios of CH4 from the most updated hydrocarbon photochemistry of the auroral regions in literature. Our study on the non-LTE and LTE emissions of the CH4 bands provides an aide for the analysis of the near-infrared data of CH4 expected from Juno, a NASA New Frontier mission, which will arrive in July, 2016 and be placed in a polar orbit to study the polar regions of Jupiter.
[B5A-1-4] 09:55~10:10
Temporal Variations of Io’s Magnetic Footprint Brightness
Suwicha Wannawichian (Chiang Mai University, Thailand) and Tatphicha Promfu
The brightness of Io‘s magnetic footprint, an indicator of electromagnetic interaction at the satellite, appears to be strongly connected to the satellite‘s distance from the plasma equator. As a result, the brightest footprints were detected when Io is near the interception location between the satellite‘s orbital plane and the plasma equator. However volcanic activities on Io show strong correlation with the equatorward shift of Jupiter main auroral oval, consequently causing the disappearance of Io footprint. The same conclusion was suggested via the observation of Jupiter‘s hectometric radio emission called HOM, which closely corresponds to Jupiter‘s auroral activity. The plasma environment near the Jovian satellites was found to vary significantly in different observational epochs. The electron density increased by approximately a factor of three from the Voyager epoch (1979) to the Galileo epoch (1995), while the electron density was found to be significantly higher (~ 5 times) in the Cassini epoch (2001). In this current study, the magnetic footprints were clearly brighter ten years ago (from peak brightness in 1998-2001) than the footprints detected in 2007. For volcanoes activities on Io in 2007, there are two clear activities in February and late May. The magnetic footprint appears to be dimmer in March 2007, expectedly resulted by the volcano activities in Feb 2007. However the magnetic footprint brightness in June appears to be slightly brighter than the footprints observed in May. The reason could be the time delay between the brightening of sodium nebula in approximately May 31st and, a while later, the enhancement of flux tube content peaks in approximately June 5th. On the other hand, Io‘s magnetic footprints were observed during June 1st - 10th which may not be yet affected by the increasing of mass outflow due to the increasing of plasma density.
[B5A-1-5] 10:10~10:25
The Study of Minor Planets at the Maidanak Observatory
O. A. Burkhonov (Ulugh Beg Astronomical Institute (UBAI) of the Uzbekistan Academy of Sciences, Uzbekistan), Sh. A. Ehgamberdiev, K. E. Ergashev, F. Yoshida, T. Ito, and Yu. N. Krugly
The international program of observations of minor planets is carried out by joint efforts of Tashkent (UBAI), Tokyo (NAOJ) and Kharkov (IAKhNU) scientific groups, which is named as "Maidanak collaboration". Maidanak observatory (Uzbekistan) is located at the west edge of Pamir Mountains and has the excellent seeing conditions. There are at least three important science aspects: (1) The main purpose of the observations of main belt asteroids (MBAs) is getting lightcurves to determine the periods of rotation of asteroids (Uzbekistan team). This task arises from the fact that the fundamental spin parameters are unknown for majority of MBAs. (2) The Multi color observations of young family asteroids (NAOJ and UBAI). The purpose is to obtain the fresh information of the family forming events which is essential for investigating the physical process of the asteroid collisional impact. (3) CCD photometry of near-Earth asteroids (NEAs) and the observations are also aimed to search for binary asteroids (IAKhNU and UBAI). It is well known the NEAs are good candidates to detecting YORP effect. During the previous period of observations in 2011-2013 years, a huge set of observational data for more than forty asteroids were gathered in the frame of Maidanak collaboration. All observational data are obtained by using the 60-cm Zeiss-600 (―North‖) telescope, 1k x 1k FLI IMG1001E CCD camera with the resolution of 0.67 arcsec/pixel, FOV of 10.7' x 10.7' and Bessel filters. The temperature of the camera was set to –30°C. The most recent multicolor observational data were obtained by using the 1.5 meter (―AZT‖) telescope with the 4096 x 4096 SNUCAM camera provided by Seoul National University. The images taken with this CCD camera have pixel scale of 0.268 arcsec/pixel and FOV of 18.1' x 18.1'. The temperature of the camera was set to –108°C. All images of studied asteroids were reduced with master bias, dark, and flat frames. Calibration frames were created using IRAF (Image Reduction and Analysis Facility). Instrumental star magnitudes were also obtained using IRAF, with zero point set to 25 mag. For estimation of extinction coefficient, we used photometric standard stars from Landolt catalogue. We used LS periodogram for period analysis of the photometric data. We have also used two other software packages: ―Period04‖ and ―cyclocode‖ to confirm the resulting period. In the frame of the research, we have determined rotation periods (for five asteroids), color indices (for three asteroids), and estimated the size and shape for one asteroid which has not been previously studied.
Session: [B5A-2] S2 : Interstellar Matter, Star Formation and the Milky Way Date: August 22, 2014 (Friday) Time: 09:00~10:25 Room: Room B (Room 103) Chair: Sun Kwok (The University of Hong Kong)
[B5A-2-1] 09:00~09:20
[Invited] Chemical Evolution in Star Formation
Jeong-Eun Lee (Kyung Hee University, Korea)
Although a detailed understanding of the process of star formation is fundamental for studies of planet formation and galaxy formation/evolution, the actual accretion process is not yet well understood. The standard model for low mass star formation predicted a constant (~2 x 10-6 Msun yr-1) steady accretion process. However, this accretion rate gives rise to the classic "luminosity problem" whereby accretion at such a rate produces accretion luminosities higher than typically observed in embedded protostars, exceeding the predictions by a factor of 10 to 100. The discovery of the Very Low Luminosity Objects (VeLLOs), which are in the embedded stage and have luminosity < 0.1 Lsun, by the Spitzer Space Telescope aggravated the luminosity problem. Episodic accretion has been suggested as one possible resolution to the luminosity problem. In the episodic accretion model, a protostar stays in the prolonged quiescent phase interrupted by short burst accretions. These two different accretion models (constant steady accretion and episodic accretion) are possibly discriminated by the chemical distributions in the envelopes and disks of protostars. Chemical evolution is the most sensitive to the temperature variation, which is affected directly by the accretion process. In constant steady accretion, the temperature in the envelope will increase gradually, while in episodic accretion, the envelope will remain cold most of time, punctuated by short hot phases. As a result, the two accretion processes should leave different chemical distributions in the envelope. In order to study the dynamical (i.e., accretion) process of star formation, therefore, the understanding of chemical evolution in the envelope is very important. We will present our model that has been developed to combine self-consistently the chemical and dynamical evolution in low mass star formation, and discuss the observational strategy to discriminate between different accretion models.
[B5A-2-2] 09:20~09:40
[Invited] Chemical Evolution of N-bearing Organic Molecules Leading to Glycine
Masatoshi Ohishi (National Astronomical Observatory of Japan, Japan)
It is widely accepted that prebiotic chemical evolution from small to large and complex molecules would have resulted in the Origin of Life. On the other hand there are two conflicting views where inorganic formation of complex organic molecules (hereafter COMs) occurred in the early Earth, on the Earth or out of the Earth. Ehrenfreund et al. (2002) indicated that exogenous delivery of COMs by comets and/or asteroids to the early Earth could be larger than their terrestrial formation by three orders of magnitude. If amino acids are formed in interstellar clouds, significant amount of them may be delivered to planets. Detection of amino acids would accelerate the discussion concerning the universality of ―life‖. So far, many trials to detect the simplest amino acid, glycine (NH2CH2COOH), were made towards Sgr B2 and other high-mass forming regions, but none of them were successful. One idea to overcome this situation would be to search for precursors to glycine. Although the chemical evolution of interstellar N-bearing COMs is poorly known, methylamine (CH3NH2) is proposed as one precursor to glycine. CH3NH2 can be formed from abundant species, CH4 and NH3, on icy dust surface. Further methyleneimine (CH2NH) would be related to CH3NH2. Another possible route to form CH3NH2 is hydrogenation (addition of hydrogen) to HCN on dust surface (Dickens et al., 1997; Kim & Kaiser et al. 2011; Theule et al. 2011): HCN → CH2NH→ CH3NH2. Figure 1 shows a possible formation route to glycine, which is based on the laboratory studies
mentioned above. In the past CH2NH was reported only in Sgr B2, W51, Orion KL, and G34.3+0.15 (Dickens et al.1997). In April 2013, we extended this survey by using the Nobeyama 45 m radio telescope towards CH3OH-rich sources. We succeeded to detect four new CH2NH sources. The derived fractional abundances of CH2NH relative to H2 are as high as 10-7, implying that CH2NH may exist widely in the ISM. If this is the case, further hydrogenation would efficiently produce CH3NH2. Based on this idea we conducted a survey of CH3NH2 towards CH2NH-rich sources in the spring of 2014, and succeeded to detect CH3NH2 towards a few sources. Further we discovered three absorption features of CH3NH2 towards Sgr B2(M) (see Figure 2). These facts would imply that CH3NH2 may widely exist in the ISM. Since it is well known that CO2 exists in most of molecular clouds, CH3NH2 could be a direct precursor candidate to glycine – the simplest amino acid— , CH3NH2-rich sources would turn into promising glycine targets by ALMA. Such studies would also accelerate discussion regarding the exogenous delivery of prebiotic species to planets and connection between the Universe and life.
[B5A-2-3] 09:40~09:55
The Physical Condition of Gas and Origin of [CII] in NGC 3184
A. S. Abdullah (Leiden Observatory, Netherlands), B. R. Brandl, A. G. G. M Tielens, B. Groves, and M. Wolfire
[CII] 158 μm is one of the brightest cooling lines in the Interstellar Medium (ISM). The brightness of [CII] makes this line a promising candidate for a tracer of star formation rate, ISM heating and cooling, and gas physics diagnostic. It has been argued that [CII] mainly comes from Photo Dissociation/Dominated Region (PDR) where photoelectric heating is the main mechanism to heat the gas. Although the general picture is well understood, the details of heating and cooling process of ISM are not well understood. The low excitation potential of C allows different physical mechanism to excite [CII]. Different studies have shown that [CII] can also come from ionized region, cold neutral medium, and molecular clouds with different gas physical condition. We present a case study of NGC 3184, a face-on spiral galaxy. NGC 3184 has been observed by Spitzer and Herschel as part of SINGS and KINGFISH programs. We present the gas physical condition in four regions of NGC 3184. The main goal of our study is to derive the gas condition in NGC 3184 and the fraction of [CII] from each of the multi-phase ISM components. We use several diagnostic lines to determine the gas properties. We define three distinguished ISM components namely : 1. Dense HII region, 2. Dense PDR, and 3. Diffuse Neutral Medium. We use MAPPINGS and dense PDR model to estimate the [CII] emission based on the gas properties from each of the components. Except for the nucleus, we find that diffuse neutral medium is the dominating contributor to the total [CII] emission. For nuclear region, the ionized gas contributes more than 40% of the [CII] emission. Surprisingly in this study we find that dense PDR contributes less than 10% to the total [CII] emission.
[B5A-2-4] 09:55~10:10
The Carbon Inventory in a Quiescent, Filamentary Molecular Cloud in G328
Catherine Braiding (University of New South Wales, Australia) and Michael Burton
We present observations of [CI] 809 GHz, CO J=1–0 115 GHz and HI 1.4 GHz spectral line emission, and calculate the corresponding C, CO and H column densities, for a sinuous, quiescent Giant Molecular Cloud about 5kpc distant along the l = 328 sightline (hereafter G328) in our Galaxy. The [CI] data comes from the High Elevation Antarctic Terahertz (HEAT) telescope, a new facility near the summit of the Antarctic plateau at Ridge A, where the atmospheric precipitable water vapour content falls to the lowest values found on the surface of the Earth. The CO dataset comes from the Mopra Southern Galactic Plane CO Survey, and the HI data from the Parkes and ATCA telescopes. The morphology and kinematics of the G328 filamentary molecular cloud are similar in [CI], CO, and HI, though the latter appears as self-absorption. The filament is ~75x5 pc long, with mass ~ 4x104 solar masses and a narrow velocity emission range of 4 km/s. The line fluxes and column densities we calculate for the three emitting species are broadly consistent with a PDR model for a giant molecular cloud exposed to the average interstellar radiation field, and the [C/CO] abundance ratio averaged through the filament is found to be approximately unity. The G328 filament is constrained to be cold (TD < 20K) by the lack of far–IR emission, shows no clear signs of star formation, from the narrow line width appears to only be mildly turbulent. We suggest that it may represent a GMC shortly after formation, or perhaps still be in the process of formation.
[B5A-2-5] 10:10~10:25
Unraveling the Physical and Chemical Properties of Planck Cold Clumps
Tie Liu (Korea Astronomy and Space Science Institute, Korea), Yuefang Wu, Kee-Tae Kim, Diego Mardones, Arnaud Belloche, Di Li, Friedrich Wyrowski, Guido Garay, Isabelle Ristorcelli, Jeong-Eun Lee, Karl M. Menten, Ken Tatematsu, Ke Wang, Leonardo Bronfman,
Stars form in dense regions within molecular clouds, called pre-stellar cores (PSCs), which provide information on the initial conditions in the process of star formation. The low dust temperature (<14 K) of Planck cold clumps/cores makes them likely to be pre-stellar objects or at the very initial stage of protostellar collapse. We have proposed follow-up observations towards these sources with ground-based telescopes (IRAM, PMO 14m, APEX, Mopra, Effelsberg 100 m and CSO). We will identify and characterize starless cores, prestellar cores and preclusters, and determine the evolutionary sequence for these cores and study their physical and chemical properties. We will also study the fragmentation of these starless Planck cold clumps to see whether the fragmentation in the earliest phase of star formation is determined by turbulence or not. This study will greatly improve our understanding of the initial conditions for star formation and core evolution. I will discuss the progress and the plans of this internationally collaborating project.
Session: [B5A-3] S3 : Stars, Exoplanets and Stellar Systems Date: August 22, 2014 (Friday) Time: 09:00~10:30 Room: Room C (Room 104) Chair: Wen-Ping Chen (National Central University)
[B5A-3-1] 09:00~09:15
[Invited] Characterising Transiting Exoplanet Systems
Daniel Bayliss (Australian National University , Australia)
Transiting planets are the key to exoplanet characterisation. The transit depth itself yields the planetary radius, and coupled with radial velocity follow-up, the true planetary mass and bulk density can be determined. A vast array of further follow-up techniques also allow in-depth characterisation of the planet. In this talk I will focus on characterising exoplanet atmospheres, temperatures, and spin-orbit alignments. Transmission spectroscopy allows us to determine the constituents of the planetary atmosphere. Such studies have detected atoms and molecules such as Na, water and methane in transiting planet atmospheres. Infra-red secondary eclipse photometry enables us to determine the temperatures of transiting planets. This in turn aids our understanding of the atmosphere of the exoplanet. Finally, the Rossiter- McLaughlin effect lets us measure the spin-orbit alignment of the star and the planet. Recent results have shown a number of transiting exoplanets are in misaligned orbits, which provide a challenge for planetary formation and migration theories.Precise characterisation relies on discovering transiting systems around bright stars. The new generations of ground and space surveys should provide these over the next five years (e.g. HATSouth, NGTS, Kepler K2, TESS). Extremely large telescopes, such as the GMT, will then be able to characterise these planets in unparalleled detail, leading to better understanding of exoplanet formation, migration, and composition.
[B5A-3-2] 09:15~09:30
[Invited] Circumbinary Planets
Liying Zhu (Chinese Academy of Sciences, China), Shengbang Qian, Wenping Liao, and Liang Liu
Most of the stars in the Galaxy are in binary systems, binaries should be the plausible hosting stars of planets. Searching for planetary companions to binaries especially evolved close binary stars (e.g., sdB-type eclipsing binaries, detached WD+dM binaries etc.) can provide insight into the formation and the ultimate fate of circumbinary planets, as well as can shed light on the late evolution of binary stars. In order to searching for the circumbinary planets around the evolved close binaries, we have monitored some evolved eclipsing binaries for several years. In this talk, I will review current observational results of circumbinary planets with different methods. Then, I will present some of our findings detected by the timing method, which has most successfully been applied to detect extrasolar planets around stars evolved beyond the first red giant branch. Finally, the fate of the orbiting circumbinary planets as well as their effects on the evolution of the host binaries will be discussed.
[B5A-3-3] 09:30~09:45
[Invited] High-Contrast Imaging of Exoplanets:Japanese Current and Future Plans
Taro Matsuo (Kyoto University, Japan)
High-contrast planet imaging observations provide us useful information on planetary atmosphere and surface environment that are complement with physical one such as mass, radius, and orbit. The Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) is a direct imaging survey for wide-orbit gas giants
and proto-planetary disks around about 500 stars as the first Subaru strategic program. Several new planets including one with unique T-dwarf type atmosphere as well as the unprecedented details of the disks have been successfully revealed in the SEEDS campaign.The next step is to detect and characterize Jovian planets at 1 to 10AU around nearby main-sequence stars. A new high-contrast instrument, called SEICA (Second-generation Exoplanet Instruments with Coronagraphic AO), for the Kyoto 4m segmented telescope is proposed as one of the next-generation Extreme Adaptive Optics. SEICA is aggressively optimized for high performance at a very small inner working angle with 10-6 detection contrast in 1-hour integration. Since this will be the first time to realize such an extreme high-contrast imaging on segmented telescopes, the SEICA project is an important step toward high contrast sciences on Extremely Large Telescopes (ELTs) – the regime in which rocky planets can be directly detected. We will begin the on-sky commissioning test in 2016 and the science observations in 2017. This talk introduces Japanese activities related to high-contrast planet imaging and then discusses possible international collaborations toward ELTs.
[B5A-3-4] 09:45~10:00
[Invited] Free Floating Planets and Initial Masss Functions
Yumiko Oasa (Saitama University, Japan)
One of the most important issues in astrophysics is to precisely determine the initial mass function (IMF). How abundant very low-mass objects such as brown dwarfs and extrasolar planets and whether the formation process and statistical properties differs among various environments are questions to be explored, yet remained unclear. We are executing near-infrared observations of various star-forming regions to search for very low-mass objects and to constrain their frequency, nature, and formation. Our photometric and spectroscopic observations with Subaru reveal significant populations of very low-luminosity YSOs with cool temperatures, some of which appear to be similar to giant planets without hosting stars, i.e. isolated planetary mass objects ("free-floating planets"). Comparison of the IMFs within the same cluster and various clusters implies that there is not any cutoff in IMF at low-mass end and very low-mass IMFs would be dependent on the forming environment. In this talk, I would like to review observational results of free-floating planets and their IMFs as well as a perspective for their future observations with GLAO, TMT and WISH.
[B5A-3-5] 10:00~10:15
Developing a Multispectral Source Finder for Direct Imaging of Exoplanets
Inseok Song (The University of Georgia, USA) and Jinhee Lee
Since the first exoplanet discovery at 1995, about 2000 exoplanets have been discovered. Radial velocity and transit methods have provided major contribution to the recognition of the ubiquity of the exoplanets in the Universe. Despite of their big contribution, these methods provide limited information about the exoplanets. The progress of technologies realizes direct imaging of the exoplanet and allows us to obtain more information about the exoplanets directly. The major difficulty to obtain images of the exoplanets is caused by high brightness contrast between the host star and the planet. Stellar coronagraph and extreme AO (adaptive optics) are used to reduce stellar light, but still there is a significant residual starlight – speckle pattern. This quasi-static speckle pattern is the main reason to make the exoplanet imaging difficult. Therefore, a post-processing method to distinguish the speckle from the target images is an important task to detect the exoplanets. The most current post- processing methods are based on empirical modeling to construct a stellar PSF, which could lead self- subtraction. In the framework of the GPI (Gemini Planet Imager, PI: B. Macintosh) project, we are developing a multispectral source finder for an AO-corrected coronagraphic imaging system. This post-processing tool is using an analytical coronagraphic PSF model based on Bayesian approach. The analytical PSF model is not correlated to the image itself unlike the other methods, so this approach could separate the speckle and the planet explicitly. With guaranteed 890 hours of Gemini time, GPI is obtaining multispectral images of young stellar systems. Here we present the performance of our tool to GPI images.
[B5A-3-6] 10:15~10:30
The MINERVA Project: Small Exoplanets from Small Telescopes
Rob Wittenmyer (University of New South Wales, Australia), John Johnson, Jason Wright, and Nate McCrady
The Kepler mission has shown that small planets are extremely common. It is likely that nearly every star in the sky hosts at least one rocky planet. We just need to look hard enough - but this requires vast amounts of telescope time. The way forward is to own the telescope. MINERVA (MINiature Exoplanet Radial Velocity Array) is a dedicated exoplanet observatory with the primary goal of discovering rocky, Earth-like planets orbiting in the habitable zone of bright, nearby stars. We have joined with Harvard, Caltech, Penn State, and Montana to build the 4-telescope MINERVA array, to be sited at Mt Hopkins in Arizona, USA. Full science operations will begin by 2015 January with all four telescopes and a stabilised spectrograph capable of high- precision Doppler velocity measurements. We will observe the 80 nearest, brightest, Sun-like stars every night for at least five years. Detailed simulations of the target list and survey strategy lead us to expect 12±3 new low-mass planets, with 3±1 in the habitable zone.
Session: [B5A-4] S4 : Galaxies, AGN and Cosmology Date: August 22, 2014 (Friday) Time: 09:00~10:25 Room: Room D (Room 105~106) Chair: Habib G. Khosroshahi (Institute for Research in Fundamental Science)
[B5A-4-1] 09:00~09:20
[Invited] Shock Waves and Nonthermal Processes in Clusters of Galaxies
Dongsu Ryu (Ulsan National Institute of Science and Technology, Korea) and Hyesung Kang
Cosmological shock waves result from supersonic flow motions induced by hierarchical clustering of nonlinear structures in the universe. These shocks govern the nature of cosmic plasma through the thermlization of gas, acceleration of nonthermal, cosmic-ray (CR) particles, generation of turbulent flow motions, and amplification of magnetic fields. We present the distribution and properties of shocks formed in cosmological simulations of a concordance LCDM universe, with a special emphasis on those in clusters of galaxies. We show that in a substantial fraction of clusters, shocks with Mach number of several or larger exist in outskirts within and around the virial radius. They are mostly accretion shocks formed by the infalling flows of the WHIM along filaments. With high Mach numbers, the acceleration of CRs is most active at the shocks. We discuss the implications of their existence for the radio and X-ray observations of clusters of galaxies.
[B5A-4-2] 09:20~09:40
[Invited] Multi-Scale Outflows in Active Galactic Nuclei
Tinggui Wang (University of Science and Technology of China, China)
AGN feedback is thought to play crucial rule in regulating the growth of galaxies as well as supermassive black holes at their centers. Outflows have been detected nearly at all scales and over a wide ionization range of the gas, and thus were considered as one form of such feedback. This talk will focus on physical properties of outflows on parsec to kiloparsec scales as traced by broad and narrow emission or absorption lines, and their correlations with other nuclear properties. We will stress the similarity of outflows on these scales, and propose a continuous outflow in the two regions. We found positive correlations between the velocity of outflow and infrared emission, suggesting a connection between outflows and hot and warm dust on these scales. We emphasize the importance of multiwavelength studies in exploring the nature of outflows.
[B5A-4-3] 09:40~09:55
Coronal Gas Flow and Its Condensation in AGN Black Hole Disk Accretion
R.E. Taam (Academia Sinica Institute of Astronomy and Astrophysics, Taiwan), B. F. Liu, E. Qiao, and W. Yuan
The nature of accretion is of fundamental interest in the study of supermassive black holes in AGN and stellar mass black holes in black hole X-ray binary systems. The accretion process in these two classes of objects is thought to be similar, however, there are several observational differences that are difficult to interpret within the same framework. We explore, in a simple model, the possibility that the flow in an accretion disk is described by more than one gaseous component, given that the physical state of gas in the central regions of galaxies is characterized by both hot, ionized and cool molecular gas components. As a first examination of this model, we consider the limiting case of the flow of a geometrically thick coronal gas component and study its condensation to a cool gas component in an optically thick accretion disk surrounding a supermassive black hole. For mass accretion rates less than about 0.01 (expressed in Eddington units), condensation does not occur and the accretion flow takes the form of a corona/ADAF. For higher mass accretion rates (> 0.02), it
is found that the coronal mass flow rate decreases and the cool mass flow rate increases with decreasing radius. Here the hot gas partially condenses to the cooler regions characterizing the underlying optically thick disk as it flows towards the black hole. For accretion rates of order 0.1, the mass flow rate of the coronal gas can attain values of order 0.02 in the innermost regions of the disk surrounding the black hole. In this picture, the X-ray emission is increased above that expected for a disk without a significant coronal mass flow, which can help to elucidate the production of strong X-ray radiation and its relative importance with respect to the optical and ultraviolet radiation in high luminosity AGN.
[B5A-4-4] 09:55~10:10
The Mass-metallicity Relation as Clues to Galaxy Feedback Models
Joo Heon Yoon (University of California Santa Barbara, USA), Crystal L. Martin, and Alaina Henry
The rise in gas-phase metallicity over the critical era when star formation activity plummets at intermediate redshifts provides a key target for cosmological models of galaxy evolution. In such models, suppression of the gas accretion rate allows the equilibrium metallicity to grow while the prescription adopted for the mass loss rate in galactic winds shapes the slope of the mass - metallicity relation below the characteristic stellar 8 mass. We examine the mass-metallicity relation down to Mstar = 10 Msun at z=0.6-0.7. For precise metallicity measurements, we conduct optical (Keck/DEIMOS) and NIR (Keck/MOSFIRE) observations for 28+45 galaxies. This is the first metallicity measurements for low-mass galaxies at intermediate redshift. Using Hα, Hβ, [OII], [OIII], & [NII] emission lines, we have achieved precise measurements of metallicity, dust reddening, and SFR. Our samples include mass-selected galaxies to test any bias based on emission-line selection. Completion of our observation will provide accurate constraints in the galaxy feedback models in cosmological simulations.
[B5A-4-5] 10:10~10:25
Apparent Inward Motion of the Parsec-scale Jet in the BL Lac Object OJ 287 Simultaneously with the Gamma-ray Flares during 2011-2012
Satoko Sawada-Satoh (National Astronomical Observatory of Japan, Japan), Kazunori Akiyama, Kotaro Niinuma, Hiroshi Nagai, Motoki Kino, Filippo D‘Ammando, Shoko Koyama, Kazuhiro Hada, Monica Orienti, Mareki Honma, Katsunori M. Shibata, and Yuji Ueno
We have carried out frequent monitoring of the BL Lac object OJ 287 in the 22-GHz band from 2010 November to 2012 September using the VLBI Exploration of Radio Astrometry (VERA) telescope array. The 22-GHz light curve of OJ 287 clearly shows three flare events: in 2011 May, 2011 October, and 2012 March, with an activity timescale of < 4 months. The second radio flare event occurred at the same time as the gamma-ray flare detected by the Large Area Telescope on-board Fermi in 2011 October, while the third radio flare seems to precede the gamma-ray flare of 2012 April. This behavior is different from what was observed during the gamma-ray flare in 2009. One jet component moved outward with an apparent superluminal speed of 11 c from 2010 November to 2011 November at a position angle of ~160 degree from North to West, and then it changed direction, moving inward with an apparent superluminal speed of 4 c. The turning point of the jet motion seemed to occur at the same time as the gamma-ray flare in 2011 October. We find a tight connection between an apparent inward motion of the parsec-scale jet and gamma-ray flaring activity seen from 2011 November to 2012 August. Higher resolution images with the Very Long Baseline Array (VLBA) at 43 GHz allow us to detect a new innermost jet component that appeared in 2011 October, simultaneously with the gamma-ray flare. The observed inward motion could be caused by the new jet component unresolved at 22 GHz in the innermost region.
Session: [B5A-5] S7 : Historical Astronomy, Astronomy Education and Public Outreach Date: August 22, 2014 (Friday) Time: 09:00~10:30 Room: Room E (Room 107) Chair: Avivah Yamani (langitselatan)
[B5A-5-1] 09:00~09:15
[Invited] Roles of the OAD: Astronomy for a Better World
Wayne Orchiston (National Astronomical Research Institute of Thailand, Thailand) and Kevin Govendor
The mission of the Office of Astronomy for Development (OAD) is to help further the use of astronomy as a tool for development by mobilizing the human and financial resources necessary in order to realize its scientific, technological and cultural benefits to society. The 3 task forces, namely (1) Astronomy for Universities and Research; (2) Astronomy for Children and Schools; (3) Astronomy for the Public, have been established to drive global activities using astronomy as a tool to stimulated development. Since 2012, the OAD has appointed three Regional Nodes. Each Node will foster the goals of the IAU Strategic Plan and liaison with the OAD and the three sector Task Forces in planning and implementing relevant programs within the region. Several activities in each Task Force will be discussed in the presentation.
[B5A-5-2] 09:15~09:30
[Invited] Astronomy for Development Approaches in Asia
Kumiko Usuda-Sato (National Astronomical Observatory of Japan, Japan) and Akihiko Tomita
The International Astronomical Union (IAU) has set up the Office of Astronomy for Development (OAD) in partnership with the South African National Research Foundation (NRF). The OAD was officially opened in 2011 at the South African Astronomical Observatory (SAAO) in Cape Town, South Africa. With the vision of ―Astronomy for a Better World‖, the mission of the OAD is to help further the use of astronomy as a tool for development by mobilizing the human and financial resources necessary in order to realize the field‘s scientific, technological and cultural benefits to society. One of the roles of the OAD is to implement the IAU‘s 10 year Strategic Plan. OAD has established the three Task Forces (TFs): (1) Astronomy for Universities and Research; (2) Astronomy for Children and Schools; and (3) Astronomy for the Public. The members are selected from all around the world. Among them, three TF1 members (from China and Indonesia) out of 11, one TF2 member (from Japan: Tomita) out of 9 members, and four TF3 members (from Hong Kong, Sri Lanka, China, and Japan: Usuda-Sato) out of 10 are from Asia region. One of the important tasks of the TFs is calling for proposals and reviewing them. In the last two years with translation support in 7 languages, the proposals relevant to astronomy for development were called. A total of 191 and 230 proposals were received in 2012 and 2013, respectively. Each TF group reviewed the proposals and reported to the IAU Extended Development Oversight Committee, and three lists (recommended, wish list, and rejected proposals) of each TF were approved. In 2012, seven-TF1, five-TF2, and six-TF3 projects were funded including 5 projects in Asia. The reports of all 2012 funded projects can be read on the OAD‘s 2014 brochure. The eight-TF1, eight-TF2, and seven-TF3 projects in 2013 including 6 projects in Asia are currently under way. Please visit the web site of www.astro4dev.org for funded projects and their reports. Many of the TFs members are related to various projects relevant to astronomy education and global networking, including Galileo Teacher Training Project (GTTP), Global Hands-On Universe (GHOU), Universe Awareness (UNAWE), Astronomers Without Borders (AWB), and many others. We share new information and discuss new ideas. We properly introduce new projects including astroEDU, crowdfunding campaign for Universe in a Box. In addition to the OAD TF works, Usuda-Sato and Tomita are involved in efforts to share our joy and enthusiasm to touch the Universe with diverse people such as people
with disabilities. We have had conferences in Tokyo twice to collect resources of such activities and to connect people who have similar goals. Our efforts meat one of the goals of OAD and some OAD funded projects. We will introduce our activities in Japan and also some OAD projects with similar approaches.
[B5A-5-3] 09:30~09:45
[Invited] OAD Activities in South East Asia
Suparerk Aukkaravittayapun (National Astronomical Research Institute of Thailand, Thailand), Boonrucksar Soonthornthum, Wayne Orchiston, Supaluck Chanthawan, and Sulisa Chariyalertsak
This paper will briefly introduce the South East Asian Regional Office of Astronomy for Development (SEA- ROAD) and its functions. Then it will present past SEA-ROAD activities, for example, the 1st COSPAR symposium, the NARIT-KASI Winter School in Radio Astronomy, and also future activities, such as the NARIT-Seminar in Modern Astronomy for secondary school students in South East Asia and the International School for Young Astronomers (ISYA2014). Lastly, roadmap of SEA-ROAD in 2014 will also be presented.
[B5A-5-4] 09:45~10:00
Talking and Star-Gazing for Thai-Japanese Astronomy and Cultural Exchange
Pisit Nitiyanant (National Astronomical Research Institute of Thailand, Thailand), Nakai Senjo, Siramas Komonjinda, and Saranya Kongjit
Astronomy Research Laboratory, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University and Japanese Studies Center, Faculty of Humanities, Chiang Mai University are co-organized ―Talking and Star-Gazing for Thai-Japanese Astronomy and Cultural Exchange‖ activities once a year in early 2012-2013 at Chiang Mai University. The objectives of this activity are for astronomers to share astronomical and cultural knowledge of Thai and Japanese, and also to share it with the public. In addition, each partner has its own objective: for Astronomy Research Laboratory, promoting outreach activity and Japanese Studies Center, providing the public with knowledge of Japanese culture. This activity is divided to 2 sections: the discussion and the stargazing. During the discussion, the Thai and Japanese knowledge was presented. For example, the main theme in 2013 is ―Comet‖ thus topics which presented are the perspective of comet, comet in Thai and Japanese historical record. Stargazing is astronomical observation with naked eye and by telescope. An average amount of audiences in these activities is 90, and the results of questionnaires by nearly half of all audiences indicate that average value for satisfaction is 92.23%. These activities provide an invaluable platform for cross-cultural exchange of astronomical knowledge and history of astronomy. They also provide general public with an oppurtunity to learn humanistic approaches to astronomy. The success of these activities is expected to have more cross-cultural events, such as Thai-Chinese and Thai-Korean exchanges.
[B5A-5-5] 10:00~10:15
Linking Young Astronomers in Southeast Asia: The SEAYAC Story
Rogel Mari Sese (Regulus SpaceTech Inc., Philippines)
The importance of involving young astronomers in developing astronomy cannot be overemphasized. This is very much true in areas where astronomy is still an emerging and minor field, such as in the Southeast Asian (SEA) region. However, recent years have seen a sudden spark of interest in developing professional astronomy within SEA, primarily for young astronomers and students. This was especially highlighted during the 2009 International Year of Astronomy. In this presentation, we introduce the Southeast Asian Young Astronomers Collaboration (SEAYAC), a recently formed organization that aims to provide a venue for professional and personal interaction for young astronomers in the SEA region. Here we present the background and rationale behind the formation of SEAYAC, its current status as well as planned future activities aimed at developing collaborations between young astronomers in the SEA region. We will also discuss the problems and challenges being faced by SEAYAC as well as its future plan of actions. It is the aim of this presentation to introduce SEAYAC to the astronomical community to encourage collaborations and interactions with both young and senior astronomers in and out of SEA region.
[B5A-5-6] 10:15~10:30
Handy Spectrograph and Its Application in Astronomical Education
In-Ok Song (Korea Advanced Institute of Science and Technology, Korea)
I applied common educational spectrograph (SV200R) in order to obtain astronomical spectra after inventing new adaptor for telescope. Experimental class and learning project in schools and public outreach are well established on imaging and photometry in terms of observations. However, experiment of astronomical spectrograph is rather hard to find because the procedures of spectral extraction and wavelength calibration is less convenient. SV2011R is 1D CCD array and thus has an advantage of unnecessary of spectral extraction. Also, basic wavelength calibration is installed on the provided software. It was adopted on 12-inch reflecting telescope in Korea Science Academy of KAIST in Busan and the spectra of bright object, Arcturus, was successfully obtained. It means one can provide educational program in a topic of astronomical spectrum. Few suggested projects are presented.
Session: [B5A-6] S6 : Observing Facilities and International Collaborations Date: August 22, 2014 (Friday) Time: 09:00~10:25 Room: Room F (Room 108) Chair: Wonyong Han (Korea Astromony and Space Science Institute)
[B5A-6-1] 09:00~09:20
[Invited] A Measurement of the Cosmic Microwave Background B-Mode Polarization with POLARBEAR
Yuji Chinone (High Energy Accelerator Research Organization, Japan)
POLARBEAR is a ground-based experiment located in the Atacama Desert of Northern Chile. The experiment is designed to measure the Cosmic Microwave Background (CMB) B-mode polarization at arcminute resolution with a beam size of 3.5 arcminutes. We started our science observations in early 2012 at 150 GHz with an array of 1,274 polarization sensitive antenna-couple Transition Edge Sensor (TES) bolometers. The CMB B-mode polarization on degree angular scales is a unique signature of primordial gravitational waves from cosmic inflation and B-modes on sub-degree scales are induced through the gravitational lensing by cosmological large-scale structure. We published the first CMB-only detection of the B-mode polarization on sub-degree scales induced by gravitational lensing in December followed by the first measurement of the B-mode power spectrum on those scales in March. I will describe the detector and hardware advances that made this possible, the results and their implications, and future plans for measuring inflationary B-modes and constraints on inflation, dark energy, and neutrino masses.
[B5A-6-2] 09:20~09:40
[Invited] GroundBIRD: a Large Angular Observation of CMB Pol. from the Ground
S. Oguri (High Energy Accelerator Research Organization, Japan)
The cosmic microwave background radiation (CMB) is an important probe to understand the beginning of the universe. In particular, the odd-parity patterns of CMB polarization, B-modes, are one of the best probes to study the inflationary universe. Whereas BICEP2 experiment has claimed the first detection of it, there is a lot of attention whether the signals come from the inflation or not. One of the important subjects is proof of an ever-presence of primordial gravitational waves (PGW), which was generated by the inflation. Wide range measurements of B-mode's spectrum will probe it. We propose a novel experiment, GroundBIRD, which achieves satellite's observation from the ground. A super high-speed scan allows us to observe the CMB polarization in a large angular scale while mitigating effects of atmospheric fluctuation. GroundBIRD is a compact radio telescope. One of the key features is very large scan range while mitigating systematic errors. In general, the range is limited by 1/f noise effect caused from detector‘s baseline fluctuation. Scan modulation, which is a CMB signal modulation by a periodic change of the line-of-sight direction, is a promising method to suppress it. In the past experiments, the left–right azimuthal scan is usually employed. Instead of the scan, we employ a high-speed rotation scan (20 rpm) without any deceleration. It allows us to expand the scan range (multipole, l) to 6 £ l £ 300. Such a wide range spectrum measurement may allow us to reveal the ever-presence of PGW. Calibration of detectors is also important to mitigate the errors. We propose the continuous calibration strategy while measuring the CMB polarization. We combine sparse wires (wire grid) set on the ground shield over the telescope and the high-speed rotation. The wire grid with the interval of a few cm creates weak linearly-polarized signal. The rotation of the telescope modulates the polarization angle of the signal. It becomes a well-defined modulated source. Therefore, the signal is useful to calibrate the detectors as well as easy to separate it from the CMB signal. We employ microwave kinetic inductance detectors (MKIDs) as detectors. A fast time response of the MKIDs (it is about 10 times faster than conventional bolometers) is well-matched with the high-speed scan of GroundBIRD,
whereas its application is the first time for the CMB observation. There are other advantages for the MKIDs, e.g., a big potential for a multiplexed readout by frequency-domain. The detectors and their readout system are under developing by Japanese collaboration group: NAOJ, RIKEN, KEK, and Okayama Univ. We have already confirmed to detect polarization signals from a CMB simulator by MKIDs. We report the status of the development of instrumental components: a vacuum chamber, radiation shields, coolers, mirrors, structures in the cryostat, and a rotating table. In particular, we succeeded to make a cold condition at 230 mK on the rotating table, which is the first achievement in the world. We plan to have commissioning observation in Japan in late 2014–2015. After that we will move the telescope to a suitable place for the CMB observation.
[B5A-6-3] 09:40~09:55
The Wendelstein 2m Telescope and it´s Instrumentation
Frank Grupp (Max Planck Institute für Extraterrestrische Physik, Germany), Florian Lang-Bardl, Claus Gössl, Ulrich Hopp, and Ralf Bender
The 2m Wendelstein telescope in the German Alps is currently in its commissioning phase. The modern Alt- Az-mounted telescope is hosting a contemporary suite of instruments. A visual light light wide field imager is covering a 0.7° diameter field utilizing a three lens filed corrector optimized for low ghost light brightness. In addition a three channel camera is imaging an uncorrected portion of 0.14° on the sky in two visual light and one near infrared channel. Beside these photometric instruments two spectrographs will be hosted at the telescope. The low to mid resolution 260channel multi object spectrograph VIRUS-W, and the highly stabilized R=70000 É chelle machine FOCES. The latter will be equipped with an astro frequency comb which, together with high end environmental and illumination stabilization will allow precise radial velocity spectroscopy down to the sub m/s regime. In the talk and paper we will introduce site and telescope, and then concentrate on the unique and technologically special features of the project such as low ghost intensity wide field imaging, high precision RV spectroscopy and the operational mode allowing a quick – semi automated – change of instruments and a flexible scheduling of observations. The latter allowing unique efficiency on a ―small‖, university owned, telescope.
[B5A-6-4] 09:55~10:10
The 2m Telescope of the Thai National Observatory
Saran Poshyachinda (National Astronomical Research Institute of Thailand, Thailand)
Thai National Observatory (TNO) was inaugurated in January 2013. However, planning and preparation started more than a decade before that. A 2.4m folded dual Nasmith Ritchey-Chretian telescope, with state- of-the-art pointing and tracking capabilities, makes it possible for the Astronomical community in Thailand to join advanced research with the international counterparts. Located at the highest mountain in Thailand at 2450m above the mean sea level, the seeing conditions at the site provide astronomers with opportunities to observe over the long dry season, from October to May, in the northern part of the country.Instruments available at the time of this report are 4k x 4k camera, low resolution spectrograph, and fast read-out camera (ULTRASPEC). The latter is a collaboration between NARIT and the Universities of Sheffield and Warwick in the UK. A medium resolution Echelle spectrograph (MRES) is due for installation in October 2014. More instruments are planned for the near future
[B5A-6-5] 10:10~10:25
U-SmART : Small Robotic Telescopes for Universities
Ranjan Gupta (The Inter-University Centre for Astronomy and Astrophysics, India), Harinder P. Singh, Shashi M. Kanbur, and Andreas Schrimpf
A group of universities have come together with the aim of designing and developing Small Aperture Robotic Telescopes (SmART) for use by students to observe variable stars and transient follow-ups. The group is deliberating on the components of the robotic system e.g. the telescope, the mount, the back-end camera, control software etc and their integration keeping in mind the scientific objectives. The prototype might then be replicated by all the participating universities to provide round the clock observations from sites spread evenly in longitude across the globe. Progress made so far is reported in this paper.
Session: [B5B-1] S1 : Solar System and Sun-Earth Interactions Date: August 22, 2014 (Friday) Time: 11:00~12:30 Room: Room A (Room 101~102) Chair: Yongha Kim (Chungnam National University)
[B5B-1-1] 11:00~11:15
The Pan-STARRS-1 Outer Solar System Key Project: A Status Report
Hsing Wen Lin (National Central University, Taiwan), Matthew Holman, and Ying Tung Chen
The Pan-STARRS-1 (PS1) survey is capable of detecting slow-moving objects in the outer solar system. Among these are Trojans, Centaurs, long-period comets, short-period comets, and trans-neptunian objects brighter than magnitude R~22. We have developed a software pipeline to search for these objects. I will present a status report for this pipeline, as well highlights from the PS1 Outer Solar System Key Project.
[B5B-1-2] 11:15~11:30
A New Theory of the Formation and Evolution of the Solar System and the Expansion of the Universe as well as the Cause and Strategy of Global Climate Change
Cuixiang Zhong (Jiangxi Normal University, China)
Since the existing hypotheses for the Solar System formation have many problems with them, the author of this paper proposed a new theory to explain the formation and evolution of the Solar System and all other star systems in the Universe. Since the Sun revolves around the centre of the Milky Way Galaxy, it must have been a satellite produced by a fixed star, just like the Moon. The growth of the Sun has gone through several phases. When the proto-sun became an Earth-sized planet, it was able to produce massive volcanic eruption to form natural satellites, these satellites unceasingly incorporated the gas and dust near the orbit to became larger and larger, farther and father away from the Sun, forming some planets around the Sun. When some planets grew large enough to produce massive volcanic eruptions to form natural satellites, some natural satellites like the Moon revolving around the Earth and Io revolving around Jupiter were formed. When the Sun grew into a proto-star much larger than Jupiter, the pressure and density of hydrogen in the centre of the proto-star became great enough for it to begin thermonuclear fusion. When the proto-star collided with another giant celestial body near the orbit or a massive volcanic eruption occurred on the proto- star, it initiated the thermonuclear fusion on the proto-star. Since the Sun‘s gravitational force is great enough to attract the needed amount of hydrogen to maintain the constant combustion, the Sun became a main- sequence star. The planets of the Solar system have been formed as the children of the Sun. Hence, the kinship among the stars in the Solar System presents a tree structure, so do the stars in the Milky Way Galaxy. Since the stars are formed from generation to generation, and their running spaces are extended unlimitedly, it shows the expansion of the Universe. About Sun-Earth Interactions, the author found that volcanic eruptions at a certain scale on some planets can indeed cause the planets‘ orbital variation, thus moving the planets away from or closing to the Sun, that is why many planets are far from the Sun. Especially on the Earth, the orbital variation of the Earth can cause global warming or cooling, even making the Earth enter an interglacial period or a glacial period. Hence, the author‘s theory has solved the cause-problem of global warming as well as the cause-problem of the alternation of glacial and interglacial periods, and also found the corresponding strategies.
[B5B-1-3] 11:30~11:45
Orbital Energy during Orbital Dynamics of Asteroid 4179 Toutatis
Endang Soegiartini (Institut Teknologi Bandung, Indonesia)
In our previous work, we investigated Asteroid 1934 CT or 1989 AC or 4179 Toutatis orbital dynamic from epoch 2012-Jul-24 (JDE2456132.5) using Mercury program package. Asteroid 4179 Toutatis is an Earth and Mars crosser orbit with semimajor axis 풂 = ퟐ. ퟓퟐퟗퟐ 풂풖 and eccentricity 풆 = ퟎ. ퟔퟐퟗퟒ . Its perihelion is 풒 = ퟎ. ퟗퟑퟕퟑ 풂풖 and aphelion is 푸 = ퟒ. ퟏퟐퟏퟏ 풂풖. After 300.000 years, asteroid 4179 Toutatis will be escaped from the Solar System, but during this time, it will have close-encountered with other planets from Earth to Uranus. As continuation of this project, we investigated its energy and orbital angular momentum changes in each close encounter. We also check the energy and orbital angular momentum of this asteroid when it escaped from the Solar System. The result is, during its orbital evolution, we found out that the energy of this asteroid usually changes and gave us negative, zero or positive.
[B5B-1-4] 11:45~12:00
Polarimetric and Morphological Imaging Analysis of Comets
Sonam Arora (Physical Research Laboratory, India) and Shashikiran Ganesh
Comets are relatively small icy bodies, often only a few kilometers in extent, that are formed in the outer solar system where temperatures are cold enough to sustain (predominately water) ices.One of the main objective behind the study of comets is to understand the origin of the Solar system. Since comets spend substantial part of their life away from the Sun, their subsurface material is considered pristine. Therefore, study of comets has proved very useful in our understanding of the origin of the solar system. We will present the detailed imaging, polarimetry and polarimetric imaging observations, data analysis techniques and interpretation of Comets C/2012 S1 (ISON) and C/2013 R1(Lovejoy) carried out from 1.2m and 0.5m telescopes installed at Gurushikhar Observatory, Mt.Abu, India. Imaging polarimetry allows us to investigate the small scale in-homogeneities in the near nucleus region of the cometary coma. We have long period imaging and these data has been used to estimate the opacity (and also the irregularities) of the cometary coma by measuring the photometric variations in the background stars as the comet passed over them. From our preliminary analysis of the comet C/2012 S1(ISON) data taken in B, V and R bands and applying Larson Sekanina Algorithms on them, we have concluded that the jet features were more prominent in R band as compared to the features in shorter wavelength bands, suggesting that the comet would have lost large amount of dust during the outburst. Hence, it may be categorized into the class of dust rich comets.
Poster Session 12:00~12:30
Chairs: Yongha Kim (Chungnam National University) Shuhrat Ehgamberdiev (Ulugh Beg Astronomical Institute)
Session: [B5B-2] S2 : Interstellar Matter, Star Formation and the Milky Way Date: August 22, 2014 (Friday) Time: 11:00~12:30 Room: Room B (Room 103) Chair: Busaba Hutawarakorn Kramer (Max Planck Institute for Radio Astronomy)
[B5B-2-1] 11:00~11:20
[Invited] Radio Variability and Magnetic Activities of Low Luminosity Protostars
Minho Choi (Korea Astronomy and Space Science Institute, Korea), Jeong-Eun Lee, and Miju Kang
The origin of stellar magnetic fields is difficult to study because typical protostars are surrounded by opaque layers of gas, such as partially ionized winds that are opaque to radio waves. Recently discovered very low- luminosity protostars present a new opportunity to directly observe the protostellar atmospheres, because their winds can be optically thin in centimeter wavelength. We surveyed very low-luminosity objects in the 8.5 GHz continuum using the Very Large Array. A radio outburst of IRAM 04191+1522 IRS was detected, and the variability timescale was about 20 days or shorter. Considering the variability timescale and flux level, the radio outbursts of these protostars may be caused by magnetic flares. However, they are probably too young and small to develop an internal convective dynamo. If the detected radio variability is owing to magnetic activities, this phenomenon may be caused by the fossil magnetic fields of interstellar origin.
[B5B-2-2] 11:20~11:40
[Invited] Molecular Outflows and the Formation of Very Low Mass Objects
Phan Bao Ngoc (International University, Vietnam)
We present our latest search for molecular outflows from very low-mass objects in rho Ophiuchi and Taurus. Our results suggest that: (1) the bipolar molecular outflow process in very low-mass objects is a scaled-down version of that in low-mass stars; (2) the outflow mass-loss and the associated mass accretion processes in very low-mass objects are possibly episodic with duration of a few thousand years; (3) the outflow mass-loss rate and the mass accretion rate during active episodes are very low and they do not significantly change for different stages of the formation process of very low-mass objects; (4) A very low mass accretion rate, possibly together with a high ratio of outflow mass-loss rate to mass accretion rate, may prevent a very low- mass core to accrete enough gas to become a star; and thus the core will end up a brown dwarf.
[B5B-2-3] 11:40~11:55
Unveiling Complex Outflow Structure of UY Aur
Tae-Soo Pyo (National Astronomical Observatory of Japan, USA), Masahiko Hayashi, Tracy L. Beck, Christoper J. Davis, and Michihiro Takami
We present high-angular resolution 1-micron spectra toward the interacting binary UY Aur obtained by Near infrared Integral Field Spectrograph (NIFS) combined with adaptive optics system Altair of GEMINI observatory. We have detected [Fe II] λ1.257 μm, He I λ1.083 μm lines from both UY Aur A (the primary source) and UY Aur B (the secondary). In [Fe II] emission, UY Aur A is brighter than UY Aur B. The blueshifted and redshifted emissions between the primary and secondary show a complicated structure. The radial velocities of the [Fe II] emission features are similar for UY Aur A and B: ∼−100 km s−1 and ∼+130 km s−1 for the blueshifted and redshifted components, respectively. Considering the morphologies of the [Fe II] emissions and bipolar outflow context, we concluded that UY Aur A drives fast and widely opening outflows with an opening angle of ∼90◦ while UY Aur B has micro collimated jet. The He I line profile of UY Aur A shows a central emission feature with deep blue and red absorptions that may be explained by stellar wind models, while that of UY Aur B shows only an emission feature.
[B5B-2-4] 11:55~12:15
[Invited] Youngest Protoplanetary Disk Discovered with ALMA
Shih-Ping Lai (National Tsing Hua University, Taiwan), Nadia Murillo, Simon Bruderer, Daniel Harsono, and Ewine F. van Dishoeck
Rotationally supported disks are critical in the star formation process. The questions of when they form and what factors influence or hinder their formation have been studied but are largely unanswered. Observations of early-stage YSOs are needed to probe disk formation. VLA1623 is a triple non-coeval protostellar system, with a weak magnetic field perpendicular to the outflow, whose Class 0 component, VLA1623A, shows a disk- like structure in continuum with signatures of rotation in line emission. We aim to determine whether this structure is in part or in whole a rotationally supported disk, i.e. a Keplerian disk, and what its characteristics are. Methods. ALMA Cycle 0 Early Science 1.3 mm continuum and C18O (2−1) observations in the extended configuration are presented here and used to perform an analysis of the disk-like structure using position– velocity (PV) diagrams and thin disk modeling with the addition of foreground absorption. The PV diagrams of the C18O line emission suggest the presence of a rotationally supported component with a radius of at least 50 AU. Kinematical modeling of the line emission shows that the disk out to 180 AU is actually rotationally supported, with the rotation described well by Keplerian rotation out to at least 150 AU, and the central source mass is ~ 0.2 M⊙ for an inclination of 55◦. Pure infall and conserved angular momentum rotation models are excluded. VLA1623A, a very young Class 0 source, presents a disk with an outer radius Rout = 180 AU with a Keplerian velocity structure out to at least 150 AU. The weak magnetic fields and recent fragmentation in this region of ρ Ophiuchus may have played a leading role in the formation of the disk.
[B5B-2-5] 12:15~12:30
Clues to the Evolution of Protoplaentary Disks in Orion A Star-Forming Region
Kyoung Hee Kim (Korea Astronomy and Space Science Institute, Korea), Dan M. Watson, and Spitzer IRS_DISKS Team
Every newly forming stellar system passes a disk dominant phase (Class II stage) in the process of star- formation. The disk around a growing young star is called a protoplanetary disk and it is the birth place of infant planets. Therefore, encrypted in the evolution of these disks is the story of the origin of planets. Our major goal in this study is to analyze a large sample of protoplanetary disks with near- and mid-IR spectra, by statistical approaches, to get clues to understand the mechanisms of protoplanetary disk evolution and planet formation. We utilized mid-IR (5-35 μm) IRS/Spitzer spectra of 319 Class II young stellar objects in Orion A star-forming region to measure spectral index of disk continuum to infer disk‘s radial and vertical properties and to derive parameters for the degree of dust processing from silicate emission features, especially around 10 μm. We also measured disk-star mass accretion rates from near-IR (0.8-2.4 μm) SpeX/IRTF spectra of 120 objects. We have examined how these properties are correlated each other and how these correlations change according to disk‘s radial structure, i.e., radially continuous disks (FDs) or transitional disks (TDs) which have radial gap or central clearing. We also have compared Orion A disks to Taurus disks to find disk characteristic evolution owing aging. From these statistical examinations, we confirmed that inner disk evolve faster than outer disk. We detected possible evolution of the degree of dust process (growing and/or crystallization) along the ages of different star-forming regions. We also separated trends in four categories according to strength and significance of correlation between properties in evolution related combinations (e.g., TD vs. FD or Orion A vs Tau). This supplies useful clues for disk evolutionary mechanisms, and it guides for the future investigation to understand disk evolution and the related characteristics.
Session: [B5B-3] S3 : Stars, Exoplanets and Stellar Systems Date: August 22, 2014 (Friday) Time: 11:00~12:30 Room: Room C (Room 104) Chair: Puji Irawati (National Astronomical Research Institute of Thailand)
[B5B-3-1] 11:00~11:15
The BIMA Project: O-C Diagrams of Eclipsing Binaries' Systems
Gabriela Kezia Haans (Institut Teknologi Bandung, Indonesia), Dhimaz Gilang Ramadhan, Saeful Akhyar, Rhisa Azaliah, Janette Suherli, Puji Irawati, Zainuddin Muhammad Arifin, Thawicharat Sarotsakulchai, Andrea Richichi, Rifqi Wisnu Aryawardhana, Hakim Luth
Eclipsing Binaries' Minima (BIMA) Monitoring Project is a CCD-based photometric observational program initiated by Bosscha Observatory – Lembang, Indonesia in June 2012. Since December 2012 National Astronomical Research Institute of Thailand (NARIT) joined BIMA Project as the main partner. This project aims to build an open-database of eclipsing binaries' minima and to establish the orbital period of each system and its variations. The project is conducted on the basis of a multisite monitoring observations on eclipsing binaries with magnitudes less than 19 mag. Differential photometry method has been applied for data reduction. The observations were carried out in the BVRI bands using three different small telescopes situated in Indonesia, Thailand, and Chile. A number of software have been developed for calculating time of minima. Up to now 92 eclipsing binaries have been observed. Out of them 20 light curves have been secured. We present and discuss the O-C diagrams from some eclipsing binaries' systems.
[B5B-3-2] 11:15~11:30
The New Eclipsing Post Common-Envelope Binary SDSS J074548.63+263123.4
Niwat Hemha (Suranaree University of Technology, Thailand), Nuanwan Sanguansak, Puji Irawati, Vik Dhillon, and Tom R. Marsh
The common-envelope process is known as one complicated phase in binary evolution. A lot of efforts have been dedicatedto study this common-envelope stage, but the many questions related to this process are yet to be answered. If one binary survives the common-envelope, the binary will emerge asa white dwarfaccompanied by low-mass main sequence star in close orbit, or often referred as the post common- envelope binary (PCEB). SDSS J074548.63+263123.4 is among the list of the newly found PCEB from the Sloan Digital Sky Survey (SDSS). This star is proposed to be a strong eclipsing system candidate due to the ellipsoidal modulation in its light curve. In this work, we aim to confirm the eclipsing nature of SDSS J0745+2631 and to determine the stellar and orbital parameters using the software Binary Maker 3. We detected the primary eclipse in the light curve of SDSS J0745+2631from our follow-up observationsin January 2014 using the ULTRASPEC instrument from the Thai National Observatory.The data obtained on 7 January 2014 in g‘ filter show an evident drop in brightness during the eclipse of the white dwarf, while this eclipse is less prominent in the data taken in the next night using clear filter. According to ourpreliminary model, we find that SDSS J0745+2631 hosts a rather hot white dwarf with an effective temperature of 50,000K.The companion star is a red dwarf star with a temperatureof 3160 K and radius 0.322R๏. The red dwarf star almost fills its Roche lobe, causing a large ellipsoidal modulation. The mass ratio of the binary given by the BM3 model is M2/M1 = 0.38.
[B5B-3-3] 11:30~11:45
Low Mass Stars in Eclipsing Binary Systems
Priyanka Chaturvedi (Physical Research Laboratory, India), Abhijit Chakraborty, B.G. Anandarao, and Vaibhav Dixit
Eclipsing Binary systems serve as an effective tool for the precise determination of masses and radii of both the components. Single lined eclipsing binary systems via radial velocity technique give us a unique opportunity to study the low mass end of the main sequence as companions to brighter primaries. Despite a large number of low mass stars present in our galaxy, masses and radii for these stars are still not determined at higher accuracies, primarily due to their fainter magnitudes in visible band. Radii for stars less massive than Sun are known to be 10% smaller theoretically than observed and temperatures are 5% higher. It is suggested that strong magnetic fields inhibit convection, which causes these stars to inflate. In general, low mass stars form an interesting area for stellar astronomers. A high-resolution echelle spectrograph, Physical Research Laboratory Advanced Radial-velocity Abu-sky Search (PARAS) working at a resolution (R) of 67000, coupled with the Physical Research Laboratory Mt. Abu, India 1.2m telescope is used for making observations of primary stars of F, G and K spectral type. One of the programs with our high resolution spectrograph PARAS operational in the wavelength regime 3800-6800 Angstroms is to look for candidates having secondaries in the low massive end of the main sequence. I will be presenting the intriguing method used to nail down the orbital parameters of these fascinating eclipsing binary systems followed by highlighting few results discovered by PARAS. We have discovered two such systems, one of them is SAO 106989 of an F7 (1.1 Msun) type primary star and a mid M dwarf by making radial velocity measurements using Physical Research Laboratory Advanced Radial velocity Abu-sky Search (PARAS) at the 1.2 m telescope at Mount Abu, India. Radial velocity measurements indicate that the mass of the M dwarf is 250 MJup with a period of 4.35 days and an eccentricity of 0.25. The other system is HD 23765 which is also a F-type main sequence star having a 0.4 Msun M dwarf orbiting at a period of 1.68 days. Similar systems discovered and analysed will contribute more to our understanding of fundamental stellar properties and make the sample of F+M and G+M binaries statistically significant.
[B5B-3-4] 11:45~12:00
Low-Resolution Spectroscopic Studies for the Globular Clusters with Multiple Populations
Dongwook Lim (Yonsei University, Korea), Sang-Il Han, Dong-Goo Roh, and Young-Wook Lee
Recent narrow-band calcium photometry discovered two distinct red giant branch (RGB) populations in some massive globular clusters (GCs) including M22, NGC 1851, and NGC 288. In order to investigate the difference in light/heavy elements abundances between the two subpopulations, we have performed low- resolution spectroscopy for stars on the two RGBs in these GCs. We find significant differences (more than 4σ) in calcium abundance from the spectroscopic HK index for both M22 and NGC 1851. We also find more than 8σ differences in CN band strength between the Ca-strong and Ca-weak subpopulations. For NGC 288, however, we detect the presence of a large difference only in the CN strength. The calcium abundances of two subpopulations in this GC are identical to within the errors. We also find interesting differences in CN-CH relations among these GCs. While CN and CH indices are correlated in M22, they show anti-correlation in NGC 288. However, NGC 1851 shows no difference in CH between two groups of stars having different CN strengths. The CN bimodality in these GCs would be explained by the pollutions from intermediate-mass asymptotic giant branch stars and/or fast-rotating massive stars. For the presence or absence of calcium bimodality and the differences in CN-CH relations, we suggest they would be best explained by how strongly type II SNe enrichment has contributed to the chemical evolutions of these GCs.
Poster Session 12:00~12:30 Chairs: Puji Irawati (National Astronomical Research Institute of Thailand) Wen-Ping Chen (National Central University)
Session: [B5B-4] S4 : Galaxies, AGN and Cosmology Date: August 22, 2014 (Friday) Time: 11:00~12:30 Room: Room D (Room 105~106) Chair: Tinggui Wang (University of Science and Technology of China)
[B5B-4-1] 11:00~11:20
[Invited] Active Galactic Nuclei Interaction with the Hot Gas Environment: Understanding from the Radio and the X-ray Data
Dharam Vir Lal (National Centre for Radio Astrophysics (NCRA-TIFR), India)
Recognition of the role of radio galaxies in the universe has been on upswing in recent years. Their colossal energy output over huge volumes is now widely believed to play a key role not only in the formation of galaxies and their super-massive blackholes, but also in the evolution of clusters of galaxies and, possibly, the cosmic web itself. More specifically, outbursts of radio galaxies have significant impact on structure formation and evolution. It has been suggested that a cool core is always required for strong radio, active galactic nucleus of bright cluster galaxy. For example, the inflation of radio bubbles in the hot gas atmospheres of clusters of galaxies plays an important role in the overall energy budget of the ICM. Regular gentle (i.e. subsonic) nuclear outbursts may be able to provide sufficient energy to the gas in the cool cores of clusters to offset radiative losses; one method to supplement the total energy input into the gas is for the radio plasma filling the cavities, seen as radio lobes, to initially drive strong shocks into the gas. We will present results from Chandra observations of the hot gas atmospheres of powerful, nearby radio galaxies in poor clusters.
[B5B-4-2] 11:20~11:40
[Invited] Novel Picture of the AGN Central Engine Established by X-ray and Optical Simultaneous Studies
Hirofumi Noda (University of Tokyo, Japan)
The primary X-ray properties reflect physical conditions of the central engine in Active Galactic Nuclei (AGNs), which is composed of accretion disks and Comptonizing coronae. In many X-ray studies, the primary signal has been assumed as a single kind of Compton continuum (e.g., Resalliti et al. 2004), and strong secondary components, affected by relativistic effects (Miniutti et al. 2007) and/or partial absorption, have been employed to reproduce the X-ray spectra. However, this assumption has not yet observationally proven, and the picture of the AGN central engine is still uncertain. To overcome this situation, we utilized a variability- assisted spectral analysis (e.g., Chrazov et al. 2001, Taylor et al. 2003), which enables us to decompose X- ray spectral components model-independently, and systematically applied it to the Suzaku archive of type I AGNs. As a result, we found that multiple kinds of Compton continua with distinct timing and spectral properties are included into a primary X-ray continuum (Noda et al. 2013; 2014), differently from the previous assumption. This gives us a novel picture that the AGN central engine consists of multiple different X-ray generating regions. To reveal the geometry of the X-ray regions around an accretion disk, we are now running X-ray and optical simultaneous monitors on several AGNs.
[B5B-4-3] 11:40~11:55
Small-Scale Environments in Galaxy Clusters: Conformity between Bright Galaxies and Their Faint Companions
Joon Hyeop Lee (Korea Astronomy and Space Science Institute, Korea), Hye-Ran Lee, Minjin Kim, Kwang-Il Seon, Sang Chul Kim, Chang Hee Ree, Jong Chul Lee, Hyunjin Jeong, Soung-Chul Yang, Jongwan Ko, and Changsu Choi
In a group environment, it is known that the properties of satellite galaxies are closely related to those of their central galaxy, such as its mass, morphology and star formation rate. Such a small-scale galactic conformity is generally expected to be relatively weak in a galaxy cluster, because the encounter time between cluster galaxies is too short to cause some direct interactions, due to the high velocity dispersion of a cluster. However, if a galaxy cluster is dynamically young enough, the galactic conformity from recently-accreted galaxy groups may remain until the group binding is completely broken up by the cluster potential. To systematically understand such small-scale environments of galaxies in galaxy clusters, we carry out photometric studies of galaxy clusters in various dynamical stages. At this time, we present the results for two galaxy clusters at z ~ 0.3: WHL J085910.0+294957 and Abell 2744. After selecting cluster members with scaling relations of galaxies, we investigate the dependence of the weighted mean colors of faint cluster galaxies on their local environments and on the properties of their adjacent bright galaxies. In WHL J085910.0+294957, we find a marginal conformity in color, in the sense that faint (–18 < Mi < –15) companions adjacent to blue bright (Mi < –18) galaxies tend to be blue, whereas such a conformity is not found in Abell 2744. These results support the idea that the small-scale conformity in galaxy clusters originates from recently-accreted groups, because WHL J085910.0+294957 is a dynamically young cluster, while Abell 2744 is a very massive cluster undergoing current cluster-cluster merger.
Poster Session 11:55~12:30 Chairs: Tinggui Wang (University of Science and Technology of China) Habib G. Khosroshahi (Institute for Research in Fundamental Science)
Session: [B5B-5] S7 : Historical Astronomy, Astronomy Education and Public Outreach Date: August 22, 2014 (Friday) Time: 11:00~12:30 Room: Room E (Room 107) Chair: Sze Leung Cheung (IAU Office for Astronomy Outreach)
[B5B-5-1] 11:00~11:15
[Invited] Documentary Series on Astronomy Research in India- Astroproject
Rakesh Rao (Enscitec Production, India)
Astroproject is an initiative to develop a Documentary Series on Astronomy, Astrophysics and Space Science related research in India. The project received sanction from the International Astronomical Union Office of Astronomy for Development (OAD) to be implemented for the year 2014. The Project concerns with documenting the Astronomy, Astrophysics and Space Science Research Institutions along with their facilities across the country. The discoveries and research carried out by the scientists in these institutions are guiding us in revealing several mysteries of the universe. This groundbreaking work specifically needs to be highlighted among the students across the educational institutions in India and also emphasise the importance of research in the field of astronomy. The final documentary series shall be screened in Schools, Colleges and Universities across India and would be done with the help of several stake holders like Research Institutions, Educational Institutes, Universities, Government bodies, Non Profit Organizations and Amateur Astronomy clubs. The documentary series shall also be dubbed in national language ―Hindi‖ so as to reach rural centres for screening. Social Networking medium on Internet shall play a major role in spreading awareness about this project. The documentary series shall be made available for free download. Also broadcasting through television programs is highly envisaged. We would like the present the work undertaken in documenting all these institutions and also present the roadmap in carrying Astronomy outreach activities across the country.
[B5B-5-2] 11:15~11:30
[Invited] The Space and Application Department of University of Science and Technology of Hanoi: Toward the Young Space and Astronomy Generation
Nguyễn Lương Quang (Canadian Institute for Theoretical Astrophysics, Canada), Yannick Giraud-Héraud, and Pierre Lesaffre
Space sciences and Space technology are symbols of a highly-developed, technology-based country. In the XXI century, they provide the best access to a powerful and sustainable economy. Recently, the Space and Applications Department has been created by the University of Science and Technology of Hanoi in Vietnam. The department aim at educating students in science, technology and engineering of all areas related to space science and astronomy The Bachelor-Master-PhD program in Space and Space Applications of USTH delivered entirely in English is a unique educational structure in Vietnam for future scientists who will participate in the development of space technology and science in the next decade. The training system at the USTH is recognized by the European Credit Transfer and Accumulation System (ECTS) and the diploma is co-accredited by Vietnam and France. In this talk, we will describe the educational program, the department structure and the outcome of the first batch of bachelor and master students.
[B5B-5-3] 11:30~11:45
[Invited] Vietnam Astronomical Society: Research, Training and Outreach Activities
Nguyen Quynh Lan (Hanoi National University of Education, Vietnam), Dinh Van Trung, and Nguyen Van Khanh
The Vietnam Astronomical Society, which is a member of the Vietnam Physical Society, has been established almost 20 years ago to promote research, education and public awareness of astronomy in Vietnam. In this presentation I will detail the activities of the VAS, in particular the undergraduate astronomy ciriculum at universities, the outreach programs to bring mainstream astronomy the general public. The main astronomical facilities in Vietnam and current research activities related to astronomy and space science using these facilities will be discussed.
[B5B-5-4] 11:45~12:00
[Invited] Observations of the Annular Eclipse on 2012 May 21 by General Public in Japan
Soma Mitsuru (National Astronomical Observatory of Japan, Japan)
An annular solar eclipse occurred on 2012 May 21 in Japan, and large cities like Tokyo, Osaka, and Nagoya were in the annular eclipse zone. As a result, about 2/3 of Japanese population were able to see the annularity in their homes. At this occasion in order to promote the interests of general public to such a great astronomical phenomenon, we had a campaign of the eclipse observations. Especially we encourage people to report if they were able to see the annularity at their places by the naked eye through eclipse eyeglasses in order to determine the limit line of the annular eclipse zone. In Japan only the northern limit line could be observed since the southern limit line was on the ocean. To tell the truth the northern limit line predicted by the NASA Eclipse Web Site and that by National Astronomical Observatory of Japan were different by about 2.7 km and people were curious to know where the actual limit line would pass. In addition I provided another limit line which should be more precise than any other prediction because I calculated it using precise lunar limb profiles I predicted from the precise lunar topographic data obtained by the Japanese lunar explorer Kaguya. Also I noted that we do not know the precise radius of the Sun (the accuracy of the known radius is about +/- 500 km) and the limit line depends on the actual radius of the Sun, so if we can determine the actual limit line from observations, we can determine the actual radius of the Sun. In the end we had about 15,000 reports of the naked eye observations through our Website. In addition there were many observation groups for which about 30,000 people in total participated in the observations. Each group reported their limit line observation result with respect to my prediction with the Kaguya lunar limb profile. Their results were like ―we determined that the limit line was about 300 m north from the prediction.‖ Their overall result was that the limit line observed by naked eye through eclipse glasses coincided with the prediction within the error of +/- 500 m. This error of the limit line location corresponds to about +/- 200 km of the radius of the Sun. Considering the accuracy of the radius hitherto obtained, this accuracy should be surprising. There was also a group of amateur observers who made video observations of Baily‘s Beads through telescopes to determine the precise radius of the Sun. Their observations are still under analysis.
Poster Session 12:00~12:30 Chairs: Sze Leung Cheung (IAU Office for Astronomy Outreach) Avivah Yamani (langitselatan)
Session: [B5B-6] S6 : Observing Facilities and International Collaborations Date: August 22, 2014 (Friday) Time: 11:00~12:30 Room: Room F (Room 108) Chair: Ranjan Gupta (IUCAA)
[B5B-6-1] 11:00~11:20
[Invited] Optical-infrared and High-energy Astronomy Collaboration at Hiroshima Astrophysical Science Center
Makoto Uemura (Hiroshima University, Japan), Michitoshi Yoshida, K. S. Kawabata, T. Mizuno, Y. T. Tanaka, H. Akitaya, Y. Utsumi, Y. Moritani, R. Itoh, Y. Fukazawa, H. Takahashi, M. Ohno, T. Ui, K. Takaki, N. Ebisuda, K. Kawaguchi, K. Mori, Y. Ohashi, Y. Kanda, M. Kawabata, K. Takata, and T. Nakaoka
Hiroshima Astrophysical Science Center (HASC) was founded in 2004 in Hiroshima University, Japan. The main mission of this institute is observational study of various transient objects including gamma-ray bursts, supernovae, novae, cataclysmic variables, and active galactic nuclei by means of multi-wavelength observations. HASC consists of three divisions; optical-infrared astronomy division, high-energy astronomy division, and theoretical astronomy division. HASC is operating a 1.5m optical-infrared telescope Kanata, which is dedicated to follow-up and monitoring observations of transient objects. The high-energy division is the key operation center of Fermi gamma-ray space telescope. HASC and the high-energy astronomy group in department of physical science of Hiroshima University are closely collaborating with each other to promote multi-wavelength time-domain astronomy. We report the recent activities of HASC and some science topics made by this multi-wavelength collaboration.
[B5B-6-2] 11:20~11:35
MIRIS, A Compact Wide-field Infrared Space Telescope
Wonyong Han (Korea Astromony and Space Science Institute, Korea), Dae-Hee Lee, Woong-Seob Jeong, Youngsik Park, Bongkon Moon, Sung-Joon Park, Jeonghyun Pyo, Il-Joong Kim, Won-Kee Park, Duk-Hang Lee, Kwang-Il Seon, Uk-Won Nam, Sang-Mok Cha, Jang-Hyun Park,
A compact infrared space telescope called MIRIS (Multi-purpose Infra-Red Imaging System) was developed by the Korea Astronomy and Space Science Institute (KASI), and launched in November 2013. The main mission of MIRIS is a Paschen-α emission line survey along the Galactic plane and cosmic infrared background (CIB) observation, particularly around the north ecliptic pole region. For these missions, a wide field of view 3.67 X 3.67 degree with an angular resolution of 51.6 arcsec and wavelength coverage from 0.9~2.0 micro-meter have been adopted for MIRIS, having optical components consisting of a 80mm main lens and four other lenses with F/2 focal ratio optics. The opto-mechanical system was carefully designed to minimize any effects from shock during the launch process and thermal variation. Also, the telescope was designed to use the passive cooling technique to maintain the temperature around 200K in order to reduce the thermal noise. A micro Stirling cooler was used to cool down the Teledyne PICNIC infrared array to 90K, which was equipped in a dewar with four filters for infrared passbands of I, H, and Paschen-α and a dual- band continuum line filter. MIRIS system was integrated into the Science and Technology Satellite-3 of Korea (STSAT-3) as its primary payload and successfully passed required tests in the laboratory, such as thermal- vacuum, vibration, and shock tests. MIRIS is now operating in sun synchronous orbits for initial tests and has observed its first images successfully.
[B5B-6-3] 11:35~11:50
An East-Asian Planet Search Network (EAPS-NET)
Hideyuki Izumiura (National Astronomical Observatory of Japan, Japan)
When the era of 8-10m class large telescopes began, 1-2m class telescopes became much less crowded, thus, they became more flexibly available for various intensive monitoring observations. The situation allowed time-domain astronomy to develop rapidly world-wide in the last decade. In particular, the discovery of the first planet in a sun-like star, 51 Peg in 1995 boosted monitoring programs for exoplanet researches via precise radial velocity measurements and high cadence precision photometry. Under such circumstances, we tried to establish an extra-solar planet search network using three 2m-class telescopes in East Asia (East Asian Planet Search Network, EAPS-NET) in 2005. The three telescopes are the 1.8m reflector at Bohyunsan Optical Astronomy Observatory in Korea, the 1.88m reflector at Okayama Astrophysical Observatory in Japan, and the 2.16m reflector at Xinglong Station in China. They are each equipped with a high resolution spectrometer to which an iodine cell was installed for precision radial velocity measurements. And we were able to begin two two-country collaborations, Korea-Japan and China-Japan, in parallel in order to carry out extra-solar planet searches in G-type giant stars by precise radial velocity measurements (Doppler technique). The collaborations are now gradually evolving toward a true three-country collaboration. In this presentation, on behalf of EAPS-NET, I will introduce EAPS-NET, then review the activities so far made concerning extra-solar planet searches with Doppler technique and related instrumentation. I will also summarize the scientific achievements including several detections of planets and brown dwarfs in G-type giants based on EAPS-NET collaboration. I will finally discuss a possible future direction of EAPS-NET in the coming age of GAIA.
[B5B-6-4] 11:50~12:05
International Collaboration for Silicon Carbide Mirror Polishing and Development
Jeong-Yeol Han (Korea Astronomy and Space Science Institute, Korea), Myung Cho, Gary Poczulp, Jakyung Nah, Hyun-Joo Seo, Kyeong-Hwan Kim, Kyung-Mo Tahk, Dong-Kyun Kim, Jinho Kim, Minho Seo, Jonggun Lee, and Sung-Yeop Han
In order to polish a Silicon Carbide (SiC) mirror material with fine surface figure of less than 20 nm rms and smooth roughness of less than 2 nm Ra, Korea Astronomy and Space Science Institute (KASI) and National Optical Astronomy Observatory (NOAO) agreed to cooperate on polishing and measuring facilities, experience and human resources for two years (2014-2015). In addition, Green Optics Co., Ltd (GO) has been interested in the SiC polishing and joined the partnership. KASI has a total responsibility of development of the SiC polishing and measurement and rent three different kinds of SiC materials (POCOTM, CoorstekTM and SSGTM corporations) from NOAO. GO will polish the SiC substrate within requirements. Optical surface requirements except surface figure and roughness are surface imperfection of less than 40 um scratch and 500 um dig. In this paper, we introduce the international collaboration for SiC mirror polishing and development. For research and development of Silicon Carbide (SiC) mirrors, Korea Astronomy and Space Science Institute (KASI) and National Optical Astronomy Observatory (NOAO) has agreed to cooperate on polishing and measuring facilities, experience and human resources for two years (2014-2015). Main goals of the SiC mirror polishing are to achieve the optical surface figure of less than 20 nm rms and the optical surface roughness of less than 2 nm Ra. In addition, Green Optics Co., Ltd (GO) has been interested in the SiC polishing and joined the partnership. KASI will be involve in the development of the SiC polishing and measurement using three different kinds of SiC materials (POCOTM, CoorstekTM and SSGTM corporations) provided by NOAO. GO will polish the SiC substrate within requirements. Additionally, requirements of the optical surface imperfections are given as: less than 40 um scratch and 500 um dig. In this paper, we introduce the international collaboration for SiC mirror polishing and development.
Poster Session 12:05~12:30 Chairs: Ranjan Gupta (IUCAA) Wonyong Han (Korea Astromony and Space Science Institute)