Diffuse Ionised Gas in Edge-On Galaxies
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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. -
A Search For" Dwarf" Seyfert Nuclei. VII. a Catalog of Central Stellar
TO APPEAR IN The Astrophysical Journal Supplement Series. Preprint typeset using LATEX style emulateapj v. 26/01/00 A SEARCH FOR “DWARF” SEYFERT NUCLEI. VII. A CATALOG OF CENTRAL STELLAR VELOCITY DISPERSIONS OF NEARBY GALAXIES LUIS C. HO The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 JENNY E. GREENE1 Department of Astrophysical Sciences, Princeton University, Princeton, NJ ALEXEI V. FILIPPENKO Department of Astronomy, University of California, Berkeley, CA 94720-3411 AND WALLACE L. W. SARGENT Palomar Observatory, California Institute of Technology, MS 105-24, Pasadena, CA 91125 To appear in The Astrophysical Journal Supplement Series. ABSTRACT We present new central stellar velocity dispersion measurements for 428 galaxies in the Palomar spectroscopic survey of bright, northern galaxies. Of these, 142 have no previously published measurements, most being rela- −1 tively late-type systems with low velocity dispersions (∼<100kms ). We provide updates to a number of literature dispersions with large uncertainties. Our measurements are based on a direct pixel-fitting technique that can ac- commodate composite stellar populations by calculating an optimal linear combination of input stellar templates. The original Palomar survey data were taken under conditions that are not ideally suited for deriving stellar veloc- ity dispersions for galaxies with a wide range of Hubble types. We describe an effective strategy to circumvent this complication and demonstrate that we can still obtain reliable velocity dispersions for this sample of well-studied nearby galaxies. Subject headings: galaxies: active — galaxies: kinematics and dynamics — galaxies: nuclei — galaxies: Seyfert — galaxies: starburst — surveys 1. INTRODUCTION tors, apertures, observing strategies, and analysis techniques. -
DGSAT: Dwarf Galaxy Survey with Amateur Telescopes
Astronomy & Astrophysics manuscript no. arxiv30539 c ESO 2017 March 21, 2017 DGSAT: Dwarf Galaxy Survey with Amateur Telescopes II. A catalogue of isolated nearby edge-on disk galaxies and the discovery of new low surface brightness systems C. Henkel1;2, B. Javanmardi3, D. Mart´ınez-Delgado4, P. Kroupa5;6, and K. Teuwen7 1 Max-Planck-Institut f¨urRadioastronomie, Auf dem H¨ugel69, 53121 Bonn, Germany 2 Astronomy Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia 3 Argelander Institut f¨urAstronomie, Universit¨atBonn, Auf dem H¨ugel71, 53121 Bonn, Germany 4 Astronomisches Rechen-Institut, Zentrum f¨urAstronomie, Universit¨atHeidelberg, M¨onchhofstr. 12{14, 69120 Heidelberg, Germany 5 Helmholtz Institut f¨ur Strahlen- und Kernphysik (HISKP), Universit¨at Bonn, Nussallee 14{16, D-53121 Bonn, Germany 6 Charles University, Faculty of Mathematics and Physics, Astronomical Institute, V Holeˇsoviˇck´ach 2, CZ-18000 Praha 8, Czech Republic 7 Remote Observatories Southern Alps, Verclause, France Received date ; accepted date ABSTRACT The connection between the bulge mass or bulge luminosity in disk galaxies and the number, spatial and phase space distribution of associated dwarf galaxies is a dis- criminator between cosmological simulations related to galaxy formation in cold dark matter and generalised gravity models. Here, a nearby sample of isolated Milky Way- class edge-on galaxies is introduced, to facilitate observational campaigns to detect the associated families of dwarf galaxies at low surface brightness. Three galaxy pairs with at least one of the targets being edge-on are also introduced. Approximately 60% of the arXiv:1703.05356v2 [astro-ph.GA] 19 Mar 2017 catalogued isolated galaxies contain bulges of different size, while the remaining objects appear to be bulgeless. -
7.5 X 11.5.Threelines.P65
Cambridge University Press 978-0-521-19267-5 - Observing and Cataloguing Nebulae and Star Clusters: From Herschel to Dreyer’s New General Catalogue Wolfgang Steinicke Index More information Name index The dates of birth and death, if available, for all 545 people (astronomers, telescope makers etc.) listed here are given. The data are mainly taken from the standard work Biographischer Index der Astronomie (Dick, Brüggenthies 2005). Some information has been added by the author (this especially concerns living twentieth-century astronomers). Members of the families of Dreyer, Lord Rosse and other astronomers (as mentioned in the text) are not listed. For obituaries see the references; compare also the compilations presented by Newcomb–Engelmann (Kempf 1911), Mädler (1873), Bode (1813) and Rudolf Wolf (1890). Markings: bold = portrait; underline = short biography. Abbe, Cleveland (1838–1916), 222–23, As-Sufi, Abd-al-Rahman (903–986), 164, 183, 229, 256, 271, 295, 338–42, 466 15–16, 167, 441–42, 446, 449–50, 455, 344, 346, 348, 360, 364, 367, 369, 393, Abell, George Ogden (1927–1983), 47, 475, 516 395, 395, 396–404, 406, 410, 415, 248 Austin, Edward P. (1843–1906), 6, 82, 423–24, 436, 441, 446, 448, 450, 455, Abbott, Francis Preserved (1799–1883), 335, 337, 446, 450 458–59, 461–63, 470, 477, 481, 483, 517–19 Auwers, Georg Friedrich Julius Arthur v. 505–11, 513–14, 517, 520, 526, 533, Abney, William (1843–1920), 360 (1838–1915), 7, 10, 12, 14–15, 26–27, 540–42, 548–61 Adams, John Couch (1819–1892), 122, 47, 50–51, 61, 65, 68–69, 88, 92–93, -
X-Ray Nature of the LINER Nuclear Sources O
A&A 460, 45–57 (2006) Astronomy DOI: 10.1051/0004-6361:20054756 & c ESO 2006 Astrophysics X-ray nature of the LINER nuclear sources O. González-Martín1, J. Masegosa1, I. Márquez1,M.A.Guerrero1, and D. Dultzin-Hacyan2 1 Instituto de Astrofísica de Andalucía, CSIC, Apartado Postal 3004, 18080 Granada, Spain e-mail: [email protected] 2 Instituto de Astronomía, UNAM, Apartado Postal 70-264, 04510 México D.F., México Received 22 December 2005 / Accepted 17 May 2006 ABSTRACT We report the results from a homogeneous analysis of the X-ray (Chandra ACIS) data available for a sample of 51 LINER galaxies selected from the catalogue by Carrillo et al. (1999, Rev. Mex. Astron. Astrofis., 35, 187) and representative of the population of bright LINER sources. The nuclear X-ray morphology has been classified by their nuclear compactness in the hard band (4.5– 8.0 keV) into 2 categories: active galactic nuclei (AGN) candidates (with a clearly identified unresolved nuclear source) and starburst (SB) candidates (without a clear nuclear source). Sixty percent of the total sample are classified as AGNs, with a median luminosity 40 −1 of LX(2−10 keV) = 2.5 × 10 erg s , which is an order of magnitude higher than for SB-like nuclei. The spectral fitting allows us to conclude that most of the objects need a non-negligible power-law contribution. When no spectral fitting can be performed (data with a low signal-to-noise ratio), the color–color diagrams allow us to roughly estimate physical parameters, such as column density, temperature of the thermal model, or spectral index for a power-law, and therefore to better constrain the origin of the X-ray emission. -
Making a Sky Atlas
Appendix A Making a Sky Atlas Although a number of very advanced sky atlases are now available in print, none is likely to be ideal for any given task. Published atlases will probably have too few or too many guide stars, too few or too many deep-sky objects plotted in them, wrong- size charts, etc. I found that with MegaStar I could design and make, specifically for my survey, a “just right” personalized atlas. My atlas consists of 108 charts, each about twenty square degrees in size, with guide stars down to magnitude 8.9. I used only the northernmost 78 charts, since I observed the sky only down to –35°. On the charts I plotted only the objects I wanted to observe. In addition I made enlargements of small, overcrowded areas (“quad charts”) as well as separate large-scale charts for the Virgo Galaxy Cluster, the latter with guide stars down to magnitude 11.4. I put the charts in plastic sheet protectors in a three-ring binder, taking them out and plac- ing them on my telescope mount’s clipboard as needed. To find an object I would use the 35 mm finder (except in the Virgo Cluster, where I used the 60 mm as the finder) to point the ensemble of telescopes at the indicated spot among the guide stars. If the object was not seen in the 35 mm, as it usually was not, I would then look in the larger telescopes. If the object was not immediately visible even in the primary telescope – a not uncommon occur- rence due to inexact initial pointing – I would then scan around for it. -
Ngc Catalogue Ngc Catalogue
NGC CATALOGUE NGC CATALOGUE 1 NGC CATALOGUE Object # Common Name Type Constellation Magnitude RA Dec NGC 1 - Galaxy Pegasus 12.9 00:07:16 27:42:32 NGC 2 - Galaxy Pegasus 14.2 00:07:17 27:40:43 NGC 3 - Galaxy Pisces 13.3 00:07:17 08:18:05 NGC 4 - Galaxy Pisces 15.8 00:07:24 08:22:26 NGC 5 - Galaxy Andromeda 13.3 00:07:49 35:21:46 NGC 6 NGC 20 Galaxy Andromeda 13.1 00:09:33 33:18:32 NGC 7 - Galaxy Sculptor 13.9 00:08:21 -29:54:59 NGC 8 - Double Star Pegasus - 00:08:45 23:50:19 NGC 9 - Galaxy Pegasus 13.5 00:08:54 23:49:04 NGC 10 - Galaxy Sculptor 12.5 00:08:34 -33:51:28 NGC 11 - Galaxy Andromeda 13.7 00:08:42 37:26:53 NGC 12 - Galaxy Pisces 13.1 00:08:45 04:36:44 NGC 13 - Galaxy Andromeda 13.2 00:08:48 33:25:59 NGC 14 - Galaxy Pegasus 12.1 00:08:46 15:48:57 NGC 15 - Galaxy Pegasus 13.8 00:09:02 21:37:30 NGC 16 - Galaxy Pegasus 12.0 00:09:04 27:43:48 NGC 17 NGC 34 Galaxy Cetus 14.4 00:11:07 -12:06:28 NGC 18 - Double Star Pegasus - 00:09:23 27:43:56 NGC 19 - Galaxy Andromeda 13.3 00:10:41 32:58:58 NGC 20 See NGC 6 Galaxy Andromeda 13.1 00:09:33 33:18:32 NGC 21 NGC 29 Galaxy Andromeda 12.7 00:10:47 33:21:07 NGC 22 - Galaxy Pegasus 13.6 00:09:48 27:49:58 NGC 23 - Galaxy Pegasus 12.0 00:09:53 25:55:26 NGC 24 - Galaxy Sculptor 11.6 00:09:56 -24:57:52 NGC 25 - Galaxy Phoenix 13.0 00:09:59 -57:01:13 NGC 26 - Galaxy Pegasus 12.9 00:10:26 25:49:56 NGC 27 - Galaxy Andromeda 13.5 00:10:33 28:59:49 NGC 28 - Galaxy Phoenix 13.8 00:10:25 -56:59:20 NGC 29 See NGC 21 Galaxy Andromeda 12.7 00:10:47 33:21:07 NGC 30 - Double Star Pegasus - 00:10:51 21:58:39 -
Global Properties of Neutral Hydrogen in Compact Groups
Global Properties of Neutral Hydrogen in Compact Groups Lisa May Walker1 Steward Observatory, University of Arizona, Tucson, AZ 85721 Kelsey E. Johnson Department of Astronomy, University of Virginia, Charlottesville, VA 22904 Sarah C. Gallagher2 Department of Physics and Astronomy, University of Western Ontario, London, ON George C. Privon1 Departamento de Astronom´ıa,Universidad de Concepci´on,Concepci´on,Chile Amanda A. Kepley1 National Radio Astronomy Observatory, Charlottesville, VA 22903 David G. Whelan1 Physics Department, Austin College, Sherman, TX 75090 Tyler D. Desjardins3 Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 Ann I. Zabludoff Department of Astronomy and Steward Observatory, University of Arizona, Tucson, AZ 85721 arXiv:1510.07628v1 [astro-ph.GA] 26 Oct 2015 ABSTRACT 1Department of Astronomy, University of Virginia, Charlottesville, VA 22904 2Visiting Fellow, Yale Center for Astronomy and Astrophysics, Department of Physics, Yale University, New Haven, CT 3Department of Physics and Astronomy, University of Western Ontario, London, ON { 2 { Compact groups of galaxies provide a unique environment to study the evo- lution of galaxies amid frequent gravitational encounters. These nearby groups have conditions similar to those in the earlier universe when galaxies were assem- bled and give us the opportunity to witness hierarchical formation in progress. To understand how the compact group environment affects galaxy evolution, we examine the gas and dust in these groups. We present new single-dish GBT neutral hydrogen (H I) observations of 30 compact groups and define a new way to quantify the group H I content as the H I-to-stellar mass ratio of the group as a whole. -
Arxiv:Astro-Ph/0304471V1 25 Apr 2003
DRAFT VERSION OCTOBER 29, 2018 Preprint typeset using LATEX style emulateapj v. 11/12/01 EXTRAPLANAR EMISSION-LINE GAS IN EDGE-ON SPIRAL GALAXIES. II. OPTICAL SPECTROSCOPY SCOTT T. MILLER1,2 AND SYLVAIN VEILLEUX1,3,4 Department of Astronomy, University of Maryland, College Park, MD 20742; stm, [email protected] Draft version October 29, 2018 ABSTRACT The results from deep long-slit spectroscopy of nine edge-on spiral galaxies with known extraplanar line emis- sion are reported. Emission from Hα, [N II]λλ6548, 6583, and [S II]λλ6716, 6731 is detected out to heights of a few kpc in all of these galaxies. Several other fainter diagnostic lines such as [O I] λ6300, [O III] λλ4959, 5007, and He I λ5876 are also detected over a smaller scale. The relative strengths, centroids and widths of the various emission lines provide constraints on the electron density, temperature, reddening, source(s) of ionization, and kinematics of the extraplanar gas. In all but one galaxy, photoionization by massive OB stars alone has difficulties explaining all of the line ratios in the extraplanar gas. Hybrid models that combine photoionization by OB stars and another source of ionization such as photoionization by turbulent mixing layers or shocks provide a better fit to the data. The (upper limits on the) velocity gradients measured in these galaxies are consistent with the predictions of the galactic fountain model to within the accuracy of the measurements. Subject headings: diffuse radiation – galaxies: halos – galaxies: ISM – galaxies: spiral – galaxies: structure 1. INTRODUCTION (TML; Slavin, Shull, & Begelman 1993) or supernovaremnants (Slavin, McKee, & Hollenbach 2000), cosmic ray heating (e.g., Emission-line diagnostics have been used successfully to de- termine the hardness of the ionizing spectrum in Galactic and Lerche & Schlickeiser 1982; Hartquist & Morfill 1986; Parker 1992), and magnetic reconnection (e.g., Raymond 1992). -
CO Observations Towards a Sample of Nearby Galaxies
RAA 2015 Vol. 15 No. 6, 785–801 doi: 10.1088/1674–4527/15/6/002 Research in http://www.raa-journal.org http://www.iop.org/journals/raa Astronomy and Astrophysics CO observations towards a sample of nearby galaxies Fa-Cheng Li1,2, Yuan-Wei Wu1 and Ye Xu1 1 Purple Mountain Observatory, & Key Laboratory for Radio Astronomy, Chinese Academy of Sciences, Nanjing 210008, China; [email protected] 2 University of Chinese Academy of Sciences, Beijing 100049, China Received 2013 November 26; accepted 2014 November 13 Abstract We have simultaneously observed 12CO, 13CO and C18O (J = 1 − 0) rotational transitions in the centers of a sample of 58 nearby spiral galaxies using the 13.7-m millimeter-wave telescope administered by Purple Mountain Observatory. Forty-two galaxies were detected in 13CO emission, but there was a null detection for C18O emission with a σ upper limit of 2 mK. The central beam ratios, R, of 12CO and 13CO range mostly from 5 to 13, with an average value of 8.1±4.2, which is slightly lower than previous estimates for normal galaxies. Clear correlations are found between 12CO and 13CO luminosities. An average X factor of 1.44 ± 0.84 × 1020 cm−2 (K km s−1)−1 is slightly lower than that in the Milky Way. Key words: galaxies: ISM — molecules: galaxies — millimeter lines: ISM — star formation: ISM 1 INTRODUCTION Molecular hydrogen, H2, constitutes a dominant part of molecular clouds in the interstellar medium in galaxies and is most closely related to star formation. The current method of studying molecular clouds in external galaxies involves the observation of rotational transitions of carbon monoxide, CO. -
Dust Temperatures in the Infrared Space Observatory1atlas of Bright Spiral Galaxies
Dust Temperatures in the Infrared Space Observatory1Atlas of Bright Spiral Galaxies George J. Bendo,2;3;4 Robert D. Joseph,3 Martyn Wells,5 Pascal Gallais,6 Martin Haas,7 Ana M. Heras,8;9 Ulrich Klaas,7 Ren´eJ.Laureijs,8;9 Kieron Leech,9;10 Dietrich Lemke,7 Leo Metcalfe,8 Michael Rowan-Robinson,11 Bernhard Schulz,9;12 and Charles Telesco13 ABSTRACT We examine far-infrared and submillimeter spectral energy distributions for galaxies in the Infrared Space Observatory Atlas of Bright Spiral Galaxies. For the 71 galaxies where we had complete 60 - 180 µm data, 1 2 we fit blackbodies with λ− emissivities and average temperatures of 31 K or λ− emissivities and average temperatures of 22 K. Except for high temperatures determined in some early-type galaxies, the temperatures show no dependence on any galaxy characteristic. For the 60 - 850 µm range in eight galaxies, we fit blackbodies 1 2 β β with λ− , λ− ,andλ− (with β variable) emissivities to the data. The best results were with the λ− emissivities, where the temperatures were 30 K and the emissivity coefficient β ranged from 0.9 to 1.9. These results produced gas to dust ratios that∼ ranged from 150 to 580, which were consistent with the ratio for the Milky Way and which exhibited relatively little dispersion compared to fits with fixed emissivities. Subject headings: galaxies: ISM | galaxies: spiral | dust 1. Introduction 2Steward Observatory, 933 North Cherry Ave, Tucson, AZ 85721 USA; [email protected] The far-infrared emission from galaxies is emitted by 3University of Hawaii, Institute for Astronomy, 2680 Woodlawn interstellar dust heated by a variety of energy sources. -
THE ULTRALUMINOUS X-RAY SOURCE POPULATION from the CHANDRA ARCHIVE of GALAXIES Douglas A
The Astrophysical Journal Supplement Series, 154:519–539, 2004 October A # 2004. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE ULTRALUMINOUS X-RAY SOURCE POPULATION FROM THE CHANDRA ARCHIVE OF GALAXIES Douglas A. Swartz,1 Kajal K. Ghosh,1 Allyn F. Tennant,2 and Kinwah Wu3 Receivved 2003 Novvember 19; accepted 2004 May 24 ABSTRACT One hundred fifty-four discrete non-nuclear ultraluminous X-ray (ULX) sources, with spectroscopically de- termined intrinsic X-ray luminosities greater than 1039 ergs sÀ1, are identified in 82 galaxies observed with Chandra’s Advanced CCD Imaging Spectrometer. Source positions, X-ray luminosities, and spectral and timing characteristics are tabulated. Statistical comparisons between these X-ray properties and those of the weaker discrete sources in the same fields (mainly neutron star and stellar-mass black hole binaries) are made. Sources above 1038 ergs sÀ1 display similar spatial, spectral, color, and variability distributions. In particular, there is no compelling evidence in the sample for a new and distinct class of X-ray object such as the intermediate-mass black holes. Eighty-three percent of ULX candidates have spectra that can be described as absorbed power laws 21 À2 with index hÀi¼1:74 and column density hNHi¼2:24 ; 10 cm ,or5 times the average Galactic column. About 20% of the ULXs have much steeper indices indicative of a soft, and likely thermal, spectrum. The locations of ULXs in their host galaxies are strongly peaked toward their galaxy centers. The deprojected radial distribution of the ULX candidates is somewhat steeper than an exponential disk, indistinguishable from that of the weaker sources.