DOCSLIB.ORG

HC3N Observations of Nearby Galaxies Xue-Jian Jiang (蒋雪健)1, 5, Jun-Zhi Wang (王均智)2, Yu Gao (高煜)1, 5, and Qiu-Sheng Gu (顾秋生)3, 4, 5

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
HC3N Observations of Nearby Galaxies Xue-Jian Jiang (蒋雪健)1, 5, Jun-Zhi Wang (王均智)2, Yu Gao (高煜)1, 5, and Qiu-Sheng Gu (顾秋生)3, 4, 5 A&A 600, A15 (2017) Astronomy DOI: 10.1051/0004-6361/201629066 & c ESO 2017 Astrophysics HC3N observations of nearby galaxies Xue-Jian Jiang (蒋êe)1; 5, Jun-Zhi Wang (王Gz)2, Yu Gao (高\)1; 5, and Qiu-Sheng Gu (~Ë生)3; 4; 5 1 Purple Mountain Observatory & Key Laboratory for Radio Astronomy, Chinese Academy of Sciences, 2 West Beijing Road, 210008 Nanjing, PR China e-mail: [email protected] 2 Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, 200030 Shanghai, PR China 3 School of Astronomy and Space Sciences, Nanjing University, 210093 Nanjing, PR China 4 Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, 210093 Nanjing, PR China 5 Collaborative Innovation Center of Modern Astronomy and Space Exploration, 210093 Nanjing, PR China Received 7 June 2016 / Accepted 22 December 2016 ABSTRACT Aims. We aim to systematically study the properties of the different transitions of the dense molecular gas tracer HC3N in galaxies. Methods. We have conducted single-dish observations of HC3N emission lines towards a sample of nearby gas-rich galaxies. HC3N(J = 2−1) was observed in 20 galaxies with the Effelsberg 100-m telescope. HC3N(J = 24−23) was observed in nine galaxies with the 10-m Submillimeter Telescope (SMT). Results. HC3N 2−1 is detected in three galaxies: IC 342, M 66, and NGC 660 (>3σ). HC3N 24−23 is detected in three galaxies: IC 342, NGC 1068, and IC 694. These are the first measurements of HC3N 2−1 in a relatively large sample of external galaxies, although the detection rate is low. For the HC3N 2−1 non-detections, upper limits (2σ) are derived for each galaxy, and stacking the non-detections is attempted to recover the weak signal of HC3N. The stacked spectrum, however, does not show any significant signs of HC3N 2−1 emission. The results are also compared with other transitions of HC3N observed in galaxies. Conclusions. The low detection rate of both transitions suggests low abundance of HC3N in galaxies, which is consistent with other + observational studies. The comparison between HC3N and HCN or HCO shows a large diversity in the ratios between HC3N and + HCN or HCO . More observations are needed to interpret the behavior of HC3N in different types of galaxies. Key words. galaxies: active – galaxies: ISM – galaxies: evolution – ISM: molecules 1. Introduction comparable to the widely-used dense gas tracer HCN and can also trace dense molecular gas around star-forming sites. HC3N Molecular lines play an essential role in our understanding has been detected in many star formation regions in the Milky of star-formation activity and galaxy evolution. With molecu- Way with several transitions from centimeter to sub-millimeter lar lines of different species and their different transitions, not (e.g., Suzuki et al. 1992). Due to the small rotational constant only can the chemical composition of the interstellar medium (∼1/13 of CO), there are many closely spaced rotational tran- be investigated, but other important physical parameters, such sitions of HC3N (separated by only 9.1 GHz) at centimeter as temperature, pressure, density, and non-collisional pumping and millimeter wavelengths, and its levels are very sensitive to mechanisms can be derived as well (e.g., Henkel et al. 1991; changes in excitation (Meier & Turner 2012). This makes it eas- Evans 1999; Fukui & Kawamura 2010; Meier & Turner 2012; ier to conduct multi-transition observations of HC3N lines than Meier et al. 2014). New facilities providing wide band and of other dense molecular gas tracers, and can help better under- highly sensitive instruments are making weak line surveys and stand the excitation conditions of star-forming regions. In con- multi-species analyses feasible, and the detections and mea- trast, the high-J lines of other dense molecular gas tracers such surements of a variety of species are helping us to reveal the as HCN and HCO+ are at very high frequencies, and it is there- gas components of galaxies, and how their abundances, densi- fore difficult to observe them with ground-based telescopes. An- ties, and ratios reflect their radiative properties. Multi-species, other advantage of using HC3N lines is that HC3N is very likely multi-transition molecular lines can be combined to identify the optically thin even in low-J transitions, due to the relatively low evolution stage of galaxies (Baan et al. 2014), because differ- abundance (Irvine et al. 1987; Lindberg et al. 2011); low opacity ent species are sensitive to different physical environments, such is important for accurate estimate of dense molecular gas mass as photo dissociation regions (PDRs) dominated by young mas- for the study of the relationship between dense molecular gas sive stars, X-rays dominated regions (XDRs) induced by active and star formation (Gao & Solomon 2004a,b; Wang et al. 2011; galactic nuclei (AGNs), and shock waves by cloud-cloud col- Zhang et al. 2014). lisions (Aladro et al. 2011; Greve et al. 2009; Costagliola et al. There have been efforts to detect HC N in nearby galaxies, 2011; Viti et al. 2014). 3 mainly in millimeter band. Observations suggest that HC3N is One of the interstellar species that benefits from the upgraded related to the warm, dense, star-forming gas, and is easily dis- facilities is cyanoacetylene (HC3N). HC3N was first detected in sociated by UV radiation (Henkel et al. 1988; Costagliola et al. 1971 at 9.0977 GHz (J = 2−1) in the Galactic star-forming 2011; Lindberg et al. 2011; Aladro et al. 2011, 2015). HC3N region Sgr B2 (Turner 1971). The critical density of HC3N is was found to be unusually luminous in NGC 4418, and it Article published by EDP Sciences A15, page 1 of7 A&A 600, A15 (2017) Table 1. The source list of the 21 galaxies observed for HC3N emission using the Effelsberg 100m and the SMT telescope. Galaxy RA (J2000) Dec VHelio Distance log LIR ∆VCO Telescope ◦ 0 00 −1 −1 h m s (km s ) (Mpc) (L ) (km s ) (1) (2) (3) (4) (5) (6) (7) (8) NGC 520 01 24 34.9 +03 47 30.0 2281 30.22 10.91 270 Effelsberg NGC 660 01 43 02.4 +13 38 42.0 850 12.33 10.49 280 Effelsberg NGC 891 02 22 33.4 +42 20 57.0 528 8.57 10.27 110 Effelsberg NGC 972 02 34 13.4 +29 18 41.0 1543 20.65 10.67 220 Effelsberg NGC 1068 02 42 41.4 −00 00 45.0 1137 13.7 11.27 280 Effelsberg & SMT IC 342 03 46 48.5 +68 05 46.0 31 4.60 10.17 72.8a Effelsberg & SMT UGC 2855 03 48 20.7 +70 07 58.0 1200 19.46 10.75 . Effelsberg UGC 2866 03 50 14.9 +70 05 40.9 1232 20.06 10.68 . Effelsberg NGC 1569 04 30 49.0 +64 50 53.0 −104 4.60 9.49 90 Effelsberg NGC 2146 06 18 39.8 +78 21 25.0 882 16.47 11.07 320 Effelsberg & SMT NGC 2403 07 36 51.3 +65 36 29.9 161 3.22 9.19 90 Effelsberg M 82 09 55 53.1 +69 40 41.0 187 3.63 10.77 150 Effelsberg & SMT NGC 3079 10 01 57.8 +55 40 47.0 1116 18.19 10.73 380 Effelsberg NGC 3310 10 38 45.9 +53 30 12.0 993 19.81 10.61 140 Effelsberg M 66 11 20 15.0 +12 59 30.0 727 10.04 10.38 180 Effelsberg IC 694 11 28 33.8 +58 33 45.0 3120 47.74 11.63 250 Effelsbergb & SMT NGC 3690 11 28 30.8 +58 33 43.0 3120 47.74 11.32 260 Effelsbergb & SMT Mrk 231 12 56 14.2 +56 52 25.0 12600 171.84 12.51 167 Effelsberg Arp 220 15 34 57.1 +23 30 10.0 5352 79.90 12.21 360 Effelsberg & SMT NGC 6240 16 52 58.9 +02 24 03.0 7160 103.86 11.85 420 SMT NGC 6946 20 34 52.6 +60 09 12.0 53 5.32 10.16 130 Effelsberg & SMT Notes. The columns are: (1) galaxy name; (2) and (3) coordinates; (4) heliocentric velocities; (5) distances; (6) total infrared luminosities (from Sanders et al. 2003); (7) CO 1−0 line width (FWHM) of the galaxies; and (8) the telescope these galaxies were observed with. (a) For IC 342, the ∆V is of CO 2−1 from Gao & Solomon(2004a); for other galaxies ∆V are of CO 1−0 from Young et al.(1995). (b) The Arp 299 system (IC 694 and NGC 3690) was observed as a single pointing by the Effelsberg. is attributed to its high abundance (10−7) as well as the in- 100-m, while the two galaxies were observed separately by the tense radiation field in the dense and warm gas at the cen- SMT 10-m. ter of NGC 4418 (Aalto et al. 2007; Costagliola & Aalto 2010). Meier & Turner(2005, 2012), Meier et al.(2011, 2014) pre- 2.1. HC N 2−1 observations with the Effelsberg 100-m sented high-resolution observations of HC3N(J = 5−4, 10−9, 3 12−11 and 16−15) of a few very nearby galaxies, and gave de- J − tailed analysis of the galactic structures and morphology traced HC3N( = 2 1) (νrest = 18:196 GHz) of 20 galaxies was observed with the Effelsberg 100-m telescope in 2010. The by HC3N and other dense gas tracers (HNC, HCN, CS, etc.).
Load more

Recommended publications
  • Multiband Counterparts of Two Eclipsing Ultraluminous X-Ray Sources in M 51
    MNRAS 000,1{16 (2017) Preprint 5 November 2018 Compiled using MNRAS LATEX style file v3.0 Multiband counterparts of two eclipsing ultraluminous X-ray sources in M 51 R. Urquhart,1? R. Soria,2;1;3 H.M. Johnston,3 M.W. Pakull,4 C. Motch,4 A. Schwope,5 J.C.A. Miller-Jones1 and G.E. Anderson1 1International Centre for Radio Astronomy Research, Curtin University, GPO Box U1987, Perth, WA 6845, Australia 2National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China 3Sydney Institute for Astronomy, School of Physics A28, The University of Sydney, Sydney, NSW 2006, Australia 4Observatoire astronomique, Universit´ede Strasbourg, CNRS, UMR 7550, 11 rue de l'Universit´e,67000, Strasbourg, France 5Leibniz-Institut f¨urAstrophysik Potsdam, An der Sternwarte 16, 14482, Potsdam, Germany Accepted XXX. Received YYY; in original form ZZZ ABSTRACT We present the discovery and interpretation of ionized nebulae around two ultra- luminous X-ray sources in M 51; both sources share the rare property of show- ing X-ray eclipses by their companion stars, and are therefore prime targets for follow-up studies. Using archival Hubble Space Telescope images, we found an elon- gated, 100-pc-long emission-line structure associated with one X-ray source (CXOM51 J132940.0+471237; ULX-1 for simplicity), and a more circular, ionized nebula at the location of the second source (CXOM51 J132939.5+471244; ULX-2 for simplicity). We observed both nebulae with the Large Binocular Telescope's Multi-Object Double Spectrograph. From our analysis of the optical spectra, we argue that the gas in the ULX-1 bubble is shock-ionized, consistent with the effect of a jet with a kinetic power of ≈2 ×1039 erg s−1.
    [Show full text]
  • The HERACLES View of the H -To-HI Ratio in Galaxies
    The HERACLES View of the H2-to-HI Ratio in Galaxies Adam Leroy (NRAO, Hubble Fellow) Fabian Walter, Frank Bigiel, the HERACLES and THINGS teams The Saturday Morning Summary • Star formation rate vs. gas relation on ~kpc scales breaks apart into: A relatively universal CO-SFR relation in nearby disks Systematic environmental scalings in the CO-to-HI ratio • The CO-to-HI ratio is a strong function of radius, total gas, and stellar surface density correlated with ISM properties: dust-to-gas ratio, pressure harder to link to dynamics: gravitational instability, arms • Interpretation: the CO-to-HI ratio traces the efficiency of GMC formation Density and dust can explain much of the observed behavior heracles Fabian Walter Erik Rosolowsky MPIA UBC Frank Bigiel Eva Schinnerer UC Berkeley THINGS plus… MPIA Elias Brinks Antonio Usero Gaelle Dumas U Hertfordshire OAN, Madrid MPIA Erwin de Blok Andreas Schruba Helmut Wiesemeyer U Cape Town IRAM … MPIA Rob Kennicutt Axel Weiss Karl Schuster Cambridge MPIfR IRAM Barry Madore Carsten Kramer Karin Sandstrom Carnegie IRAM MPIA Michele Thornley Daniela Calzetti Kelly Foyle Bucknell UMass MPIA Collaborators The HERA CO-Line Extragalactic Survey First maps Leroy et al. (2009) • IRAM 30m Large Program to map CO J = 2→1 line • Instrument: HERA receiver array operating at 230 GHz • 47 galaxies: dwarfs to starbursts and massive spirals -2 • Very wide-field (~ r25) and sensitive (σ ~ 1-2 Msun pc ) NGS The HI Nearby Galaxy Survey HI Walter et al. (2008), AJ Special Issue (2008) • VLA HI maps of 34 galaxies:
    [Show full text]
  • Big Halpha Kinematical Sample of Barred Spiral Galaxies - I
    BhaBAR: Big Halpha kinematical sample of BARred spiral galaxies - I. Fabry-Perot Observations of 21 galaxies O. Hernandez, C. Carignan, P. Amram, L. Chemin, O. Daigle To cite this version: O. Hernandez, C. Carignan, P. Amram, L. Chemin, O. Daigle. BhaBAR: Big Halpha kinematical sample of BARred spiral galaxies - I. Fabry-Perot Observations of 21 galaxies. Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P - Oxford Open Option A, 2005, 360 Issue 4, pp.1201. 10.1111/j.1365-2966.2005.09125.x. hal-00014446 HAL Id: hal-00014446 https://hal.archives-ouvertes.fr/hal-00014446 Submitted on 26 Jan 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Mon. Not. R. Astron. Soc. 360, 1201–1230 (2005) doi:10.1111/j.1365-2966.2005.09125.x BHαBAR: big Hα kinematical sample of barred spiral galaxies – I. Fabry–Perot observations of 21 galaxies O. Hernandez,1,2 † C. Carignan,1 P. Amram,2 L. Chemin1 and O. Daigle1 1Observatoire du mont Megantic,´ LAE, Universitede´ Montreal,´ CP 6128 succ. centre ville, Montreal,´ Quebec,´ Canada H3C 3J7 2Observatoire Astronomique de Marseille Provence et LAM, 2 pl.
    [Show full text]
  • CO Multi-Line Imaging of Nearby Galaxies (COMING) IV. Overview Of
    Publ. Astron. Soc. Japan (2018) 00(0), 1–33 1 doi: 10.1093/pasj/xxx000 CO Multi-line Imaging of Nearby Galaxies (COMING) IV. Overview of the Project Kazuo SORAI1, 2, 3, 4, 5, Nario KUNO4, 5, Kazuyuki MURAOKA6, Yusuke MIYAMOTO7, 8, Hiroyuki KANEKO7, Hiroyuki NAKANISHI9 , Naomasa NAKAI4, 5, 10, Kazuki YANAGITANI6 , Takahiro TANAKA4, Yuya SATO4, Dragan SALAK10, Michiko UMEI2 , Kana MOROKUMA-MATSUI7, 8, 11, 12, Naoko MATSUMOTO13, 14, Saeko UENO9, Hsi-An PAN15, Yuto NOMA10, Tsutomu, T. TAKEUCHI16 , Moe YODA16, Mayu KURODA6, Atsushi YASUDA4 , Yoshiyuki YAJIMA2 , Nagisa OI17, Shugo SHIBATA2, Masumichi SETA10, Yoshimasa WATANABE4, 5, 18, Shoichiro KITA4, Ryusei KOMATSUZAKI4 , Ayumi KAJIKAWA2, 3, Yu YASHIMA2, 3, Suchetha COORAY16 , Hiroyuki BAJI6 , Yoko SEGAWA2 , Takami TASHIRO2 , Miho TAKEDA6, Nozomi KISHIDA2 , Takuya HATAKEYAMA4 , Yuto TOMIYASU4 and Chey SAITA9 1Department of Physics, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan 2Department of Cosmosciences, Graduate School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan 3Department of Physics, School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan 4Division of Physics, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan 5Tomonaga Center for the History of the Universe (TCHoU), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan 6Department of Physical Science, Osaka Prefecture University, Gakuen 1-1,
    [Show full text]
  • Precollimator for X-Ray Telescope (Stray-Light Baffle) Mindrum Precision, Inc Kurt Ponsor Mirror Tech/SBIR Workshop Wednesday, Nov 2017
    Mindrum.com Precollimator for X-Ray Telescope (stray-light baffle) Mindrum Precision, Inc Kurt Ponsor Mirror Tech/SBIR Workshop Wednesday, Nov 2017 1 Overview Mindrum.com Precollimator •Past •Present •Future 2 Past Mindrum.com • Space X-Ray Telescopes (XRT) • Basic Structure • Effectiveness • Past Construction 3 Space X-Ray Telescopes Mindrum.com • XMM-Newton 1999 • Chandra 1999 • HETE-2 2000-07 • INTEGRAL 2002 4 ESA/NASA Space X-Ray Telescopes Mindrum.com • Swift 2004 • Suzaku 2005-2015 • AGILE 2007 • NuSTAR 2012 5 NASA/JPL/ASI/JAXA Space X-Ray Telescopes Mindrum.com • Astrosat 2015 • Hitomi (ASTRO-H) 2016-2016 • NICER (ISS) 2017 • HXMT/Insight 慧眼 2017 6 NASA/JPL/CNSA Space X-Ray Telescopes Mindrum.com NASA/JPL-Caltech Harrison, F.A. et al. (2013; ApJ, 770, 103) 7 doi:10.1088/0004-637X/770/2/103 Basic Structure XRT Mindrum.com Grazing Incidence 8 NASA/JPL-Caltech Basic Structure: NuSTAR Mirrors Mindrum.com 9 NASA/JPL-Caltech Basic Structure XRT Mindrum.com • XMM Newton XRT 10 ESA Basic Structure XRT Mindrum.com • XMM-Newton mirrors D. de Chambure, XMM Project (ESTEC)/ESA 11 Basic Structure XRT Mindrum.com • Thermal Precollimator on ROSAT 12 http://www.xray.mpe.mpg.de/ Basic Structure XRT Mindrum.com • AGILE Precollimator 13 http://agile.asdc.asi.it Basic Structure Mindrum.com • Spektr-RG 2018 14 MPE Basic Structure: Stray X-Rays Mindrum.com 15 NASA/JPL-Caltech Basic Structure: Grazing Mindrum.com 16 NASA X-Ray Effectiveness: Straylight Mindrum.com • Correct Reflection • Secondary Only • Backside Reflection • Primary Only 17 X-Ray Effectiveness Mindrum.com • The Crab Nebula by: ROSAT (1990) Chandra 18 S.
    [Show full text]
  • Radio Continuum and CO Emission in Star-Forming Galaxies
    A&A 385, 412–424 (2002) Astronomy DOI: 10.1051/0004-6361:20020140 & c ESO 2002 Astrophysics Radio continuum and CO emission in star-forming galaxies M. Murgia1,A.Crapsi1,2, L. Moscadelli3, and L. Gregorini1,4 1 Istituto di Radioastronomia del CNR, Via Gobetti 101, 40129, Bologna, Italy 2 Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125, Firenze, Italy 3 Osservatorio Astronomico di Cagliari, Loc. Poggio dei Pini, Strada 54, 09012 Capoterra (CA), Italy 4 Dipartimento di Fisica, Universit`a di Bologna, Via B. Pichat 6/2, 40127 Bologna, Italy Received 30 October 2001 / Accepted 23 January 2002 Abstract. We combine the radio continuum images from the NRAO VLA Sky Survey with the CO-line observations from the extragalactic CO survey of the Five College Radio Astronomy Observatory to study the relationship between molecular gas and the star formation rate within the disks of 180 spiral galaxies at 4500 resolution. We find a tight correlation between these quantities. On average, the ratio between the radio continuum and the CO emission is constant, within a factor of 3, both inside the same galaxy and from galaxy to galaxy. The mean star formation efficiency deduced from the radio continuum corresponds to convert 3.5% of the available molecular gas into stars on a time scale of 108 yr and depends weakly on general galaxy properties, such as Hubble type or nuclear activity. A comparison is made with another similar analysis performed using the Hα luminosity as star formation indicator. The overall agreement we find between the two studies reinforces the use of the radio luminosity as star formation rate indicator not only on global but also on local scales.
    [Show full text]
  • 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.
    [Show full text]
  • Arxiv:Astro-Ph/0309446V1 16 Sep 2003 N Necocigmlclrcod(..Mk38 Eke Al
    The Neutral ISM in Starburst Galaxies ASP Conference Series, Vol. xxx, 2003 S. Aalto, S. H¨uttemeister, A. Pedlar Extragalactic water masers in bright IRAS sources A. Tarchi1,2, C. Henkel3, A.B. Peck4, N. Nagar5, L. Moscadelli2, and K.M. Menten3 1Instituto di Radioastronomia, CNR, Bologna, Italy 2Osservatorio Astronomico di Cagliari, Capoterra (CA), Italy 3MPIfR, Bonn, Germany 4Harvard-Smithsonian CfA, SMA Project, Hilo, HI, USA 5Kapteyn Astronomical Institute, Groningen, the Netherlands Abstract. We report the results of a search for 22 GHz water maser emission in IRAS-bright galaxies, using the 100-m Effelsberg telescope. In particular, we present the details of four new maser detections (IC 342, NGC 2146, NGC 3556, and Arp 299) and follow-up interferometric stud- ies. A comparison between water maser detection rates derived in the present study and those in previous similar surveys is also presented. 1. Introduction To date, there is evidence for a total of three distinct classes of extragalactic H2O masers: i) H2O megamasers (with isotropic luminosities Liso > 10 L⊙) associated with accretion disks in active galaxies (e.g. NGC 4258, Miyoshi et al. 1995) ii) H2O megamasers resulting from an interaction between the nuclear radio jet and an encroaching molecular cloud (e.g. Mrk 348, Peck et al. 2001, 2003) iii) weaker H2O masers, the ‘kilomasers’ (with Liso < 10 L⊙), often associated with prominent star forming regions in large scale galactic disks, and, thus far arXiv:astro-ph/0309446v1 16 Sep 2003 found in galaxies containing bright IRAS (Infrared Astronomical Satellite) point sources (e.g. NGC 2146, Tarchi et al.
    [Show full text]
  • HALOS, STARBURSTS, and SUPERBUBBLES in SPIRALS Joel
    HALOS, STARBURSTS, AND SUPERBUBBLES IN SPIRALS Joel N. Bregman Department of Astronomy, University of Michigan, Ann Arbor, MI 48109-1090 [email protected] ABSTRACT Detectable quantities of interstellar material are present in the halo of the Milky Way galaxy and in a few edge-on spiral galaxies, largely in the form of neutral atomic gas, warm ionized material, and cosmic rays. Theoretical and observational arguments suggest that million degree gas should be present also, so sensitive ROSAT observations have been made of the large nearby edge- on spiral galaxies for the purpose of detecting hot extraplanar gas. Of the six brightest non-starburst edge-on galaxies, three exhibit extraplanar X-ray emission: NGC 891, NGC 4631, and NGC 4565. In NGC 891, the extended emission has a density scale height of 7 kpc and an extent along the disk of 13 kpc in diameter. This component is close to hydrostatic equilibrium, has a luminosity of 4.4 • 1039 erg s -1, and a mass of 10s Mo. Extended and structured extraplanar hot gas is seen around the interacting edge-on spiral NGC 4631, with X-ray emission associated with a giant loop of Ha and HI emission; spurs of X- ray emission extending from the disk are seen also. Hot gas is expected to enter the halo through superbubble breakout, and a search for superbubbles in normal spiral galaxies have shown that these phenomena are present, but of low surface brightness and are detected in only a few instances. Unlike the normal spiral galaxies where the gas is bound to the systems, the hot gas in starburst galaxies is being expelled.
    [Show full text]
  • How to Make $1000 with Your Telescope! – 4 Stargazers' Diary
    Fort Worth Astronomical Society (Est. 1949) February 2010 : Astronomical League Member Club Calendar – 2 Opportunities & The Sky this Month – 3 How to Make $1000 with your Telescope! – 4 Astronaut Sally Ride to speak at UTA – 4 Aurgia the Charioteer – 5 Stargazers’ Diary – 6 Bode’s Galaxy by Steve Tuttle 1 February 2010 Sunday Monday Tuesday Wednesday Thursday Friday Saturday 1 2 3 4 5 6 Algol at Minima Last Qtr Moon Æ 5:48 am 11:07 pm Top ten binocular deep-sky objects for February: M35, M41, M46, M47, M50, M93, NGC 2244, NGC 2264, NGC 2301, NGC 2360 Top ten deep-sky objects for February: M35, M41, M46, M47, M50, M93, NGC 2261, NGC 2362, NGC 2392, NGC 2403 7 8 9 10 11 12 13 Algol at Minima Morning sports a Moon at Apogee New Moon Æ super thin crescent (252,612 miles) 8:51 am 7:56 pm Moon 8:00 pm 3RF Star Party Make use of the New Moon Weekend for . better viewing at the Dark Sky Site See Notes Below New Moon New Moon Weekend Weekend 14 15 16 17 18 19 20 Presidents Day 3RF Star Party Valentine’s Day FWAS Traveler’s Guide Meeting to the Planets UTA’s Maverick Clyde Tombaugh Ranger 8 returns Normal Room premiers on Speakers Series discovered Pluto photographs and NatGeo 7pm Sally Ride “Fat Tuesday” Ash Wednesday 80 years ago. impacts Moon. 21 22 23 24 25 26 27 Algol at Minima First Qtr Moon Moon at Perigee Å (222,345 miles) 6:42 pm 12:52 am 4 pm {Low in the NW) Algol at Minima Æ 9:43 pm Challenge binary star for month: 15 Lyncis (Lynx) Challenge deep-sky object for month: IC 443 (Gemini) Notable carbon star for month: BL Orionis (Orion) 28 Notes: Full Moon Look for a very thin waning crescent moon perched just above and slightly right of tiny Mercury on the morning of 10:38 pm Feb.
    [Show full text]
  • Hubble Sights Galaxy Stuck in the Middle 30 April 2018
    Hubble sights galaxy stuck in the middle 30 April 2018 from Earth in the constellation of Camelopardalis (the Giraffe). Camelopardalis contains many other interesting deep-sky objects, including the open cluster NGC 1502, the elegant Kemble's Cascade asterism, and the starburst galaxy NGC 2146. Provided by NASA Credit: ESA/Hubble & NASA, A. Fillipenko This pretty, cloud-like object may not look much like a galaxy—it lacks the well-defined arms of a spiral galaxy, or the reddish bulge of an elliptical—but it is in fact something known as a lenticular galaxy. Lenticular galaxies sit somewhere between the spiral and elliptical types; they are disk-shaped, like spirals, but they no longer form large numbers of new stars and thus contain only aging populations of stars, like ellipticals. NGC 2655's core is extremely luminous, resulting in its additional classification as a Seyfert galaxy: a type of active galaxy with strong and characteristic emission lines. This luminosity is thought to be produced as matter is dragged onto the accretion disk of a supermassive black hole sitting at the center of NGC 2655. The structure of NGC 2655's outer disk, on the other hand, appears calmer, but it is oddly shaped. The complex dynamics of the gas in the galaxy suggest that it may have had a turbulent past, including mergers and interactions with other galaxies. NGC 2655 is located about 80 million light-years 1 / 2 APA citation: Hubble sights galaxy stuck in the middle (2018, April 30) retrieved 28 September 2021 from https://phys.org/news/2018-04-hubble-sights-galaxy-stuck-middle.html This document is subject to copyright.
    [Show full text]
  • IRAC Near-Infrared Features in the Outer Parts of S4G Galaxies
    Mon. Not. R. Astron. Soc. 000, 1{26 (2014) Printed 15 June 2018 (MN LATEX style file v2.2) Spitzer/IRAC Near-Infrared Features in the Outer Parts of S4G Galaxies Seppo Laine,1? Johan H. Knapen,2;3 Juan{Carlos Mu~noz{Mateos,4:5 Taehyun Kim,4;5;6;7 S´ebastienComer´on,8;9 Marie Martig,10 Benne W. Holwerda,11 E. Athanassoula,12 Albert Bosma,12 Peter H. Johansson,13 Santiago Erroz{Ferrer,2;3 Dimitri A. Gadotti,5 Armando Gil de Paz,14 Joannah Hinz,15 Jarkko Laine,8;9 Eija Laurikainen,8;9 Kar´ınMen´endez{Delmestre,16 Trisha Mizusawa,4;17 Michael W. Regan,18 Heikki Salo,8 Kartik Sheth,4;1;19 Mark Seibert,7 Ronald J. Buta,20 Mauricio Cisternas,2;3 Bruce G. Elmegreen,21 Debra M. Elmegreen,22 Luis C. Ho,23;7 Barry F. Madore7 and Dennis Zaritsky24 1Spitzer Science Center - Caltech, MS 314-6, Pasadena, CA 91125, USA 2Instituto de Astrof´ısica de Canarias, E-38205 La Laguna, Tenerife, Spain 3Departamento de Astrof´ısica, Universidad de La Laguna, 38206 La Laguna, Spain 4National Radio Astronomy Observatory/NAASC, Charlottesville, 520 Edgemont Road, VA 22903, USA 5European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago, Chile 6Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Korea 7The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101, USA 8Division of Astronomy, Department of Physics, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland 9Finnish Centre of Astronomy with ESO (FINCA), University of Turku, V¨ais¨al¨antie20, FIN-21500 Piikki¨o 10Max-Planck Institut f¨urAstronomie, K¨onigstuhl17 D-69117 Heidelberg, Germany 11Leiden Observatory, Leiden University, P.O.
    [Show full text]