Object Index
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
We Had a Great Time on the Trip. We Had Some Representatives from the Vandenberg and Santa Barbara Clubs Along with Us for the Trip
We had a great time on the trip. We had some representatives from the Vandenberg and Santa Barbara clubs along with us for the trip. The most notable thing on the trip up was a stop in La Canada Flintridge to refuel the bus and get a bite to eat. I pulled out my PST Coronado and did a little impromptu public Sun Gazing. The Sun was pretty active with a number of platform prominences as well as the ever-present flame types. A distinct sunspot group in a very disturbed area of the Sun with a bright spot had me wondering if there was a flare in progress (There wasn’t.) The patrons at the tables outside didn’t seem to object to seeing the Sun either. I had a little bit of a scare when we first got up to the gate as a couple of people who were going to meet us there were nowhere to be seen. Fortunately one of them was already on the grounds and the other showed up while we were in the Museum. Relief! As it turned out we all went on the tour of the grounds. Our tour guide Greg gave us a tour starting outside the 60” Dome. He talked about the various Solar Telescopes -the old Snow telescope which was always a non-performer because of the design of the building- too many air currents. He talked about the rivalry over the 60 and 150 ft tower solar instruments (looks like UCLA won this one over USC.) And we got a good look at the 150 ft tower. -
Astronomy & Astrophysics Background Galaxies As Reddening
A&A 371, 895–907 (2001) Astronomy DOI: 10.1051/0004-6361:20010467 & c ESO 2001 Astrophysics Background galaxies as reddening probes throughout the Magellanic Clouds C. M. Dutra1,3,E.Bica1,3,J.J.Clari´a2,3,A.E.Piatti2,3, and A. V. Ahumada2,3 1 Instituto de Fisica-UFRGS, CP 15051, CEP 91501-970 POA – RS, Brazil 2 Observatorio Astron´omico de C´ordoba, Laprida 854, 5000, C´ordoba, Argentina 3 Visiting Astronomer, Complejo Astron´omico El Leoncito operated under agreement between the Consejo Nacional de Investigaciones Cient´ıficas y T´ecnicas de la Rep´ublica Argentina and the National Universities of La Plata, C´ordoba and San Juan Received 3 January 2001 / Accepted 23 March 2001 Abstract. We study the spectral properties in the range 3600 A–6800˚ A˚ of the nuclear region of galaxies behind the Magellanic Clouds. The radial velocities clarified the nature of the objects as background galaxies or extended objects belonging to the Clouds. For most galaxies behind the main bodies of the LMC and SMC, radial velocities were measured for the first time. In the present sample typical LMC background galaxies are nearby (4000 <V(km s−1) < 6000), while SMC’s are considerably more distant (10 000 <V(km s−1) < 20 000). We determine the reddening in each line of sight by matching a reddening-free galaxy template with comparable stellar population. For the LMC main body we derive a combined Milky Way and internal reddening value E(B−V )MW+i =0.120.10, while for the SMC E(B−V )MW+i =0.050.05. -
Luminous Blue Variables
Review Luminous Blue Variables Kerstin Weis 1* and Dominik J. Bomans 1,2,3 1 Astronomical Institute, Faculty for Physics and Astronomy, Ruhr University Bochum, 44801 Bochum, Germany 2 Department Plasmas with Complex Interactions, Ruhr University Bochum, 44801 Bochum, Germany 3 Ruhr Astroparticle and Plasma Physics (RAPP) Center, 44801 Bochum, Germany Received: 29 October 2019; Accepted: 18 February 2020; Published: 29 February 2020 Abstract: Luminous Blue Variables are massive evolved stars, here we introduce this outstanding class of objects. Described are the specific characteristics, the evolutionary state and what they are connected to other phases and types of massive stars. Our current knowledge of LBVs is limited by the fact that in comparison to other stellar classes and phases only a few “true” LBVs are known. This results from the lack of a unique, fast and always reliable identification scheme for LBVs. It literally takes time to get a true classification of a LBV. In addition the short duration of the LBV phase makes it even harder to catch and identify a star as LBV. We summarize here what is known so far, give an overview of the LBV population and the list of LBV host galaxies. LBV are clearly an important and still not fully understood phase in the live of (very) massive stars, especially due to the large and time variable mass loss during the LBV phase. We like to emphasize again the problem how to clearly identify LBV and that there are more than just one type of LBVs: The giant eruption LBVs or h Car analogs and the S Dor cycle LBVs. -
Arxiv:Astro-Ph/9808091V1 10 Aug 1998 Pc Eecp Cec Nttt,Wihi Prtdb the NAS5-26555
To appear in the Astronomical Journal (accepted 1998 August 10) WFPC2 OBSERVATIONS OF STAR CLUSTERS IN THE MAGELLANIC CLOUDS. II. THE OLDEST STAR CLUSTERS IN THE SMALL MAGELLANIC CLOUD1 Kenneth J. Mighell2 Kitt Peak National Observatory, National Optical Astronomy Observatories3, P. O. Box 26732, Tucson, AZ 85726-6732 Electronic mail: [email protected] Ata Sarajedini4 Department of Physics and Astronomy, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132 Electronic mail: [email protected] Rica S. French5 Middle Tennessee State University, Physics & Astronomy Department, WPS 219, P. O. Box 71, Murfreesboro, TN 37132 Electronic mail: [email protected] arXiv:astro-ph/9808091v1 10 Aug 1998 1 Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS5-26555. 2 Guest User, Canadian Astronomy Data Centre, which is operated by the Dominion Astrophysical Observatory for the National Research Council of Canada’s Herzberg Institute of Astrophysics. 3NOAO is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation. 4Hubble Fellow 5Based on research conducted at NOAO as part of the Research Experiences for Undergraduates program. – 2 – ABSTRACT We present our analysis of archival Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) observations in F450W ( B) and F555W ( V ) of the ∼ ∼ intermediate-age populous star clusters NGC 121, NGC 339, NGC 361, NGC 416, and Kron 3 in the Small Magellanic Cloud. -
RATIOS and STAR FORMATION EFFICIENCIES in SUPERGIANT H Ii REGIONS
The Astrophysical Journal, 788:167 (7pp), 2014 June 20 doi:10.1088/0004-637X/788/2/167 C 2014. The American Astronomical Society. All rights reserved. Printed in the U.S.A. ENHANCEMENT OF CO(3–2)/CO(1–0) RATIOS AND STAR FORMATION EFFICIENCIES IN SUPERGIANT H ii REGIONS Rie E. Miura1,2, Kotaro Kohno3,4, Tomoka Tosaki5, Daniel Espada1,6,7, Akihiko Hirota8, Shinya Komugi1, Sachiko K. Okumura9, Nario Kuno7,8, Kazuyuki Muraoka10, Sachiko Onodera10, Kouichiro Nakanishi1,6,7, Tsuyoshi Sawada1,6, Hiroyuki Kaneko11, Tetsuhiro Minamidani8, Kosuke Fujii1,2, and Ryohei Kawabe1,6 1 National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; [email protected] 2 Department of Astronomy, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 133-0033, Japan 3 Institute of Astronomy, School of Science, The University of Tokyo, Osawa, Mitaka, Tokyo 181-0015, Japan 4 Research Center for Early Universe, School of Science, The University of Tokyo, Hongo, Bunkyo, Tokyo 113-0033, Japan 5 Joetsu University of Education, Yamayashiki-machi, Joetsu, Niigata 943-8512, Japan 6 Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura 763-0355, Santiago, Chile 7 Department of Astronomical Science, The Graduate University for Advanced Studies (Sokendai), 2-21-1 Osawa, Mitaka, Tokyo 181-0015, Japan 8 Nobeyama Radio Observatory, Minamimaki, Minamisaku, Nagano 384-1805, Japan 9 Department of Mathematical and Physical Sciences, Faculty of Science, Japan Woman’s University, Mejirodai 2-8-1, Bunkyo, Tokyo 112-8681, Japan 10 Osaka Prefecture University, -
BIBLIOGRAPHY Richard De Grijs (24 September 2021)
BIBLIOGRAPHY Richard de Grijs (24 September 2021) 1. Refereed Articles (in reverse chronological order) (y: Papers written by my students/postdocs in which I had a major hand and whom I supervised directly.) (242) Niederhofer F., Cioni M.-R.L., Schmidt T., Bekki K., de Grijs R., Ivanov V.D., Oliveira J.M., Ripepi V., Subramanian S., van Loon J.T., 2021, The VMC survey. XLVI. Stellar proper motions within the centre of the Large Magellanic Cloud, MNRAS, submitted (241) Schmidt T., Cioni M.-R.L., Niederhofer F., Bekki K., Bell C.P.M., de Grijs R., El Youssoufi D., Ivanov V.D., Oliveira J.M., Ripepi V., van Loon J.T., 2021, The VMC survey. XLV. Proper motion of the outer LMC and the impact of the SMC, A&A, submitted (240) James D., Subramanian S., Omkumar A.O., Mary A., Bekki K., Cioni M.-R.L., de Grijs R., El Youssoufi D., Kartha S.S., Niederhofer F., van Loon J.T., 2021, Presence of red giant population in the foreground stellar sub-structure of the Small Magellanic Cloud, MNRAS, in press (239) y Choudhury S., de Grijs R., Bekki K., Cioni M.-R.L., Ivanov V.D., van Loon J.T., Miller A.E., Niederhofer F., Oliveira J.M., Ripepi V., Sun N.-C., Subramanian S., 2021, The VMC survey. XLIV. Mapping metallicity trends in the Large Magellanic Cloud using near-infrared passbands, MNRAS, 507, 4752 (arXiv:2108.10529) (238) de Grijs R., 2021, Non-Western efforts to solve the ‘Longitude Problem’. I. China, JAHH, submitted (237) Smith M.W.L., Eales S.A., Williams T.G., Lee B., Li Z.-N., Barmby P., Bureau M., Chapman S., Cho B.S., Chung A., Chung E.J., Chung -
Authentic Data in the Classroom with the Sloan Digital Sky Survey
Proc. of the GHOU 2007 in Tokyo Authentic Data in the Classroom with the Sloan Digital Sky Survey M. Jordan Raddick* 1 Student engagement with the process of science is a proven part of highquality science education, but authentic science activities can be difficult in astronomy because of the difficulty students have in taking data. This paper describes how the Sloan Digital Sky Survey (SDSS) contributes to solving this problem by making its entire dataset available to students and the public, free of charge. The survey's SkyServer website (http://skyserver.sdss.org) includes simple tools to browse and search the data, as well as projects that use the data to teach science. The dataset is also a great source of independent research projects for students. 1. Introduction for each star or galaxy, including magnitudes and object types. Images are available as FITS files. Movements in science education reform in the The survey also measures followup spectra for United States and around the world frequently cite stars, galaxies and quasars. These spectra run from engagement with the process of science as a key 3800 to 9200 Ångstroms, and have a resolution of component of effective science learning, and 1.8 Ångstroms per pixel. They are available as GIF scientific inquiry as an important part of images or FITS files, and detailed line widths and understanding science [1,2]. strengths are available for each spectral line. Laboratory activities in other science subjects frequently make use of student inquiry labs, in which 3. SkyServer students make their own observations, interpret the results, and draw conclusions. -
Direct N-Body Simulations of Globular Clusters--III. Palomar\, 4 on An
MNRAS 000, 1–11 (2013) Preprint 14 September 2018 Compiled using MNRAS LATEX style file v3.0 Direct N-body simulations of globular clusters – III. Palomar4 on an eccentric orbit Akram Hasani Zonoozi1⋆, Hosein Haghi1, Pavel Kroupa2,3, Andreas H.W. K¨upper4†, Holger Baumgardt5 1Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), PO Box 11365-9161, Zanjan, Iran 2Helmholtz-Institut f¨ur Strahlen-und Kernphysik (HISKP), Universit¨at Bonn, Nussallee 14-16, D-53115 Bonn, Germany 3Charles University in Prague, Faculty of Mathematics and Physics, Astronomical Institute, V Holeˇsoviˇck´ach 2, CZ-180 00 Praha 8, Czech Republic 4Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027, USA 5School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia Accepted .... Received ABSTRACT Palomar 4 is a low-density globular cluster with a current mass ≈ 30000 M⊙in the outer halo of the Milky Way with a two-body relaxation time of the order of a Hubble time. Yet, it is strongly mass segregated and contains a stellar mass function depleted of low-mass stars. Pal 4 was either born this way or it is a result of extraordi- nary dynamical evolution. Since two-body relaxation cannot explain these signatures alone, enhanced mass loss through tidal shocking may have had a strong influence on Pal 4. Here, we compute a grid of direct N-body simulations to model Pal4 on various eccentric orbits within the Milky Way potential to find likely initial conditions that reproduce its observed mass, half-light radius, stellar MF-slope and line-of-sight ve- locity dispersion. -
14476 (Stsci Edit Number: 4, Created: Wednesday, September 7, 2016 4:28:02 PM EST) - Overview
Proposal 14476 (STScI Edit Number: 4, Created: Wednesday, September 7, 2016 4:28:02 PM EST) - Overview 14476 - A collision reversal in HD 5980 Cycle: 24, Proposal Category: GO (Availability Mode: SUPPORTED) INVESTIGATORS Name Institution E-Mail Dr. Yael Naze (PI) (ESA Member) (Contact) Universite de Liege [email protected] Dr. D. John Hillier (CoI) University of Pittsburgh [email protected] Dr. Gloria Koenigsberger (CoI) (Contact) Universidad Nacional Autonoma de Mexico (UNAM) [email protected] Dr. Julian M. Pittard (CoI) (ESA Member) University of Leeds [email protected] Dr. Michael F. Corcoran (CoI) Universities Space Research Association [email protected] Dr. Gregor Rauw (CoI) (ESA Member) Universite de Liege [email protected] VISITS Visit Targets used in Visit Configurations used in Visit Orbits Used Last Orbit Planner Run OP Current with Visit? 01 (1) HD-5980 STIS/CCD 2 07-Sep-2016 17:28:00.0 yes CCDFLAT STIS/FUV-MAMA 2 Total Orbits Used ABSTRACT HD 5980 provides a unique laboratory for studying the properties of wind-wind collisions. It contains one of only two binary systems having a WR- star in orbit with a LBV. The latter star has been observed to undergo major changes in its wind structure over the past 35 years, implying changes in the geometry and emitting conditions of the wind-wind collision region. Ten years ago, when the LBV wind was very strong, XMM observations revealed X-ray emission consistent with the shock cone wrapping around the WR component. Since then, the wind strength has significantly declined, implying that the collision shock cone may be inverting its orientation. -
Expected Differences Between AGB Stars in the LMC and the SMC Due to Differences in Chemical Composition
New Views of the Magellanic Clouds fA U Symposium, Vol. 190, 1999 Y.-H. Chu, N.B. Suntzef], J.E. Hesser, and D.A. Bohlender, eds. Expected Differences between AGB Stars in the LMC and the SMC Due to Differences in Chemical Composition Ju. Frantsman Astronomical Institute, Latvian University, Raina Blvd. 19, Riga, LV-1586, LATVIA Abstract. Certain aspects of the AGB population, such as the relative number of M and N stars, the mass loss rates, and the initial masses of carbon- oxygen cores, depend on the initial heavy element abundance Z. I have calculated synthetic populations of AGB stars for different initial Z values taking into consideration the evolution of single and close binary stars. I present the results of population syntheses of AGB stars in clusters as a function of different initial chemical compositions. The relation for the tip luminosity of AGB stars versus cluster age as a function of Z is presented and is used to determine the ages for a number of clusters in the LMC and the SMC, including clusters with no previous age determinations. Population simulations show that for low heavy element abundance (Z = 0.001) few M stars are formed with respect to the number of carbon stars. However, the total number of all AGB stars in clusters is not affected by the initial chemical composition. As a result of the evolution of close binary components after the mass exchange, an increase in the range of limiting values of the thermal pulsing AGB star luminosities is expected. The difference between the maximum luminosity on the AGB of single star and the luminosity of a star after a mass exchange event in a close binary system may be as great as 1 magnitude for very young clusters. -
From Luminous Hot Stars to Starburst Galaxies
9780521791342pre CUP/CONT July 9, 2008 11:48 Page-i FROM LUMINOUS HOT STARS TO STARBURST GALAXIES Luminous hot stars represent the extreme upper mass end of normal stellar evolution. Before exploding as supernovae, they live out their lives of only a few million years with prodigious outputs of radiation and stellar winds which dramatically affect both their evolution and environments. A detailed introduction to the topic, this book connects the astrophysics of mas- sive stars with the extremes of galaxy evolution represented by starburst phenomena. A thorough discussion of the physical and wind parameters of massive stars is pre- sented, together with considerations of their birth, evolution, and death. Hll galaxies, their connection to starburst galaxies, and the contribution of starburst phenomena to galaxy evolution through superwinds, are explored. The book concludes with the wider cosmological implications, including Population III stars, Lyman break galaxies, and gamma-ray bursts, for each of which massive stars are believed to play a crucial role. This book is ideal for graduate students and researchers in astrophysics who are interested in massive stars and their role in the evolution of galaxies. Peter S. Conti is an Emeritus Professor at the Joint Institute for Laboratory Astro- physics (JILA) and theAstrophysics and Planetary Sciences Department at the University of Colorado. Paul A. Crowther is a Professor of Astrophysics in the Department of Physics and Astronomy at the University of Sheffield. Claus Leitherer is an Astronomer with the Space Telescope Science Institute, Baltimore. 9780521791342pre CUP/CONT July 9, 2008 11:48 Page-ii Cambridge Astrophysics Series Series editors: Andrew King, Douglas Lin, Stephen Maran, Jim Pringle and Martin Ward Titles available in the series 10. -
Fundamental Parameters of Wolf-Rayet Stars VI
Astron. Astrophys. 320, 500–524 (1997) ASTRONOMY AND ASTROPHYSICS Fundamental parameters of Wolf-Rayet stars VI. Large Magellanic Cloud WNL stars? P.A.Crowther and L.J. Smith Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK Received 5 February 1996 / Accepted 26 June 1996 Abstract. We present a detailed, quantitative study of late WN Key words: stars: Wolf-Rayet;mass-loss; evolution; fundamen- (WNL) stars in the LMC, based on new optical spectroscopy tal parameters – galaxies: Magellanic Clouds (AAT, MSO) and the Hillier (1990) atmospheric model. In a pre- vious paper (Crowther et al. 1995a), we showed that 4 out of the 10 known LMC Ofpe/WN9 stars should be re-classified WN9– 10. We now present observations of the remaining stars (except the LBV R127), and show that they are also WNL (WN9–11) 1. Introduction stars, with the exception of R99. Our total sample consists of 17 stars, and represents all but one of the single LMC WN6– Quantitative studies of hot luminous stars in galaxies are im- 11 population and allows a direct comparison with the stellar portant for a number of reasons. First, and probably foremost, parameters and chemical abundances of Galactic WNL stars is the information they provide on the effect of the environment (Crowther et al. 1995b; Hamann et al. 1995a). Previously un- on such fundamental properties as the mass-loss rate and stellar published ultraviolet (HST-FOS, IUE-HIRES) spectroscopy are evolution. In the standard picture (e.g. Maeder & Meynet 1987) presented for a subset of our programme stars.