CO Observations Towards a Sample of Nearby Galaxies
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A Multivariate Statistical Analysis of Spiral Galaxy Luminosities. I. Data and Results
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server A Multivariate Statistical Analysis of Spiral Galaxy Luminosities. I. Data and Results Alice Shapley California Institute of Technology, Pasadena CA, 91125, USA G. Fabbiano Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 P. B. Eskridge Ohio State University, Dept. of Astronomy, 140 W 18th Ave, Columbus, OH 43210 ABSTRACT We have performed a multiparametric analysis of luminosity data for a sample of 234 normal spiral and irregular galaxies observed in X-rays with the Einstein Observatory. This sample is representative of S and Irr galaxies, with a good coverage of morphological types and absolute magnitudes. In addition to X-ray and optical data, we have compiled H-band magnitudes, IRAS near- and far-infrared, and 6cm radio continuum observations for the sample from the literature. We have also performed a careful compilation of distance estimates. We have explored the effect of morphology by dividing the sample into early (S0/a-Sab), intermediate (Sb-Sbc), and late-type (Sc-Irr) subsamples. The data were analysed with bivariate and multivariate survival analysis techniques that make full use of all the information available in both detections and limits. We find that most pairs of luminosities are correlated when considered individually, and this is not due to a distance bias. Different luminosity-luminosity correlations follow different power-law relations. Contrary to previous reports, the LX LB correlation follows a power-law with exponent − larger than 1. Both the significances of some correlations and their power-law relations are morphology dependent. -
Near-Infrared Luminosity Relations and Dust Colors L
A&A 578, A47 (2015) Astronomy DOI: 10.1051/0004-6361/201525817 & c ESO 2015 Astrophysics Obscuration in active galactic nuclei: near-infrared luminosity relations and dust colors L. Burtscher1, G. Orban de Xivry1, R. I. Davies1, A. Janssen1, D. Lutz1, D. Rosario1, A. Contursi1, R. Genzel1, J. Graciá-Carpio1, M.-Y. Lin1, A. Schnorr-Müller1, A. Sternberg2, E. Sturm1, and L. Tacconi1 1 Max-Planck-Institut für extraterrestrische Physik, Postfach 1312, Gießenbachstr., 85741 Garching, Germany e-mail: [email protected] 2 Raymond and Beverly Sackler School of Physics & Astronomy, Tel Aviv University, 69978 Ramat Aviv, Israel Received 5 February 2015 / Accepted 5 April 2015 ABSTRACT We combine two approaches to isolate the AGN luminosity at near-IR wavelengths and relate the near-IR pure AGN luminosity to other tracers of the AGN. Using integral-field spectroscopic data of an archival sample of 51 local AGNs, we estimate the fraction of non-stellar light by comparing the nuclear equivalent width of the stellar 2.3 µm CO absorption feature with the intrinsic value for each galaxy. We compare this fraction to that derived from a spectral decomposition of the integrated light in the central arcsecond and find them to be consistent with each other. Using our estimates of the near-IR AGN light, we find a strong correlation with presumably isotropic AGN tracers. We show that a significant offset exists between type 1 and type 2 sources in the sense that type 1 MIR X sources are 7 (10) times brighter in the near-IR at log LAGN = 42.5 (log LAGN = 42.5). -
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. -
Stellar Tidal Streams As Cosmological Diagnostics: Comparing Data and Simulations at Low Galactic Scales
RUPRECHT-KARLS-UNIVERSITÄT HEIDELBERG DOCTORAL THESIS Stellar Tidal Streams as Cosmological Diagnostics: Comparing data and simulations at low galactic scales Author: Referees: Gustavo MORALES Prof. Dr. Eva K. GREBEL Prof. Dr. Volker SPRINGEL Astronomisches Rechen-Institut Heidelberg Graduate School of Fundamental Physics Department of Physics and Astronomy 14th May, 2018 ii DISSERTATION submitted to the Combined Faculties of the Natural Sciences and Mathematics of the Ruperto-Carola-University of Heidelberg, Germany for the degree of DOCTOR OF NATURAL SCIENCES Put forward by GUSTAVO MORALES born in Copiapo ORAL EXAMINATION ON JULY 26, 2018 iii Stellar Tidal Streams as Cosmological Diagnostics: Comparing data and simulations at low galactic scales Referees: Prof. Dr. Eva K. GREBEL Prof. Dr. Volker SPRINGEL iv NOTE: Some parts of the written contents of this thesis have been adapted from a paper submitted as a co-authored scientific publication to the Astronomy & Astrophysics Journal: Morales et al. (2018). v NOTE: Some parts of this thesis have been adapted from a paper accepted for publi- cation in the Astronomy & Astrophysics Journal: Morales, G. et al. (2018). “Systematic search for tidal features around nearby galaxies: I. Enhanced SDSS imaging of the Local Volume". arXiv:1804.03330. DOI: 10.1051/0004-6361/201732271 vii Abstract In hierarchical models of galaxy formation, stellar tidal streams are expected around most galaxies. Although these features may provide useful diagnostics of the LCDM model, their observational properties remain poorly constrained. Statistical analysis of the counts and properties of such features is of interest for a direct comparison against results from numeri- cal simulations. In this work, we aim to study systematically the frequency of occurrence and other observational properties of tidal features around nearby galaxies. -
1. Introduction
THE ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 122:109È150, 1999 May ( 1999. The American Astronomical Society. All rights reserved. Printed in U.S.A. GALAXY STRUCTURAL PARAMETERS: STAR FORMATION RATE AND EVOLUTION WITH REDSHIFT M. TAKAMIYA1,2 Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637; and Gemini 8 m Telescopes Project, 670 North Aohoku Place, Hilo, HI 96720 Received 1998 August 4; accepted 1998 December 21 ABSTRACT The evolution of the structure of galaxies as a function of redshift is investigated using two param- eters: the metric radius of the galaxy(Rg) and the power at high spatial frequencies in the disk of the galaxy (s). A direct comparison is made between nearby (z D 0) and distant(0.2 [ z [ 1) galaxies by following a Ðxed range in rest frame wavelengths. The data of the nearby galaxies comprise 136 broad- band images at D4500A observed with the 0.9 m telescope at Kitt Peak National Observatory (23 galaxies) and selected from the catalog of digital images of Frei et al. (113 galaxies). The high-redshift sample comprises 94 galaxies selected from the Hubble Deep Field (HDF) observations with the Hubble Space Telescope using the Wide Field Planetary Camera 2 in four broad bands that range between D3000 and D9000A (Williams et al.). The radius is measured from the intensity proÐle of the galaxy using the formulation of Petrosian, and it is argued to be a metric radius that should not depend very strongly on the angular resolution and limiting surface brightness level of the imaging data. It is found that the metric radii of nearby and distant galaxies are comparable to each other. -
Radio Sources in Low-Luminosity Active Galactic Nuclei
A&A 392, 53–82 (2002) Astronomy DOI: 10.1051/0004-6361:20020874 & c ESO 2002 Astrophysics Radio sources in low-luminosity active galactic nuclei III. “AGNs” in a distance-limited sample of “LLAGNs” N. M. Nagar1, H. Falcke2,A.S.Wilson3, and J. S. Ulvestad4 1 Arcetri Observatory, Largo E. Fermi 5, Florence 50125, Italy 2 Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, 53121 Bonn, Germany e-mail: [email protected] 3 Department of Astronomy, University of Maryland, College Park, MD 20742, USA Adjunct Astronomer, Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA e-mail: [email protected] 4 National Radio Astronomy Observatory, PO Box 0, Socorro, NM 87801, USA e-mail: [email protected] Received 23 January 2002 / Accepted 6 June 2002 Abstract. This paper presents the results of a high resolution radio imaging survey of all known (96) low-luminosity active galactic nuclei (LLAGNs) at D ≤ 19 Mpc. We first report new 2 cm (150 mas resolution using the VLA) and 6 cm (2 mas resolution using the VLBA) radio observations of the previously unobserved nuclei in our samples and then present results on the complete survey. We find that almost half of all LINERs and low-luminosity Seyferts have flat-spectrum radio cores when observed at 150 mas resolution. Higher (2 mas) resolution observations of a flux-limited subsample have provided a 100% (16 of 16) detection rate of pc-scale radio cores, with implied brightness temperatures ∼>108 K. The five LLAGNs with the highest core radio fluxes also have pc-scale “jets”. -
Distances to PHANGS Galaxies: New Tip of the Red Giant Branch Measurements and Adopted Distances
MNRAS 501, 3621–3639 (2021) doi:10.1093/mnras/staa3668 Advance Access publication 2020 November 25 Distances to PHANGS galaxies: New tip of the red giant branch measurements and adopted distances Gagandeep S. Anand ,1,2‹† Janice C. Lee,1 Schuyler D. Van Dyk ,1 Adam K. Leroy,3 Erik Rosolowsky ,4 Eva Schinnerer,5 Kirsten Larson,1 Ehsan Kourkchi,2 Kathryn Kreckel ,6 Downloaded from https://academic.oup.com/mnras/article/501/3/3621/6006291 by California Institute of Technology user on 25 January 2021 Fabian Scheuermann,6 Luca Rizzi,7 David Thilker ,8 R. Brent Tully,2 Frank Bigiel,9 Guillermo A. Blanc,10,11 Med´ eric´ Boquien,12 Rupali Chandar,13 Daniel Dale,14 Eric Emsellem,15,16 Sinan Deger,1 Simon C. O. Glover ,17 Kathryn Grasha ,18 Brent Groves,18,19 Ralf S. Klessen ,17,20 J. M. Diederik Kruijssen ,21 Miguel Querejeta,22 Patricia Sanchez-Bl´ azquez,´ 23 Andreas Schruba,24 Jordan Turner ,14 Leonardo Ubeda,25 Thomas G. Williams 5 and Brad Whitmore25 Affiliations are listed at the end of the paper Accepted 2020 November 20. Received 2020 November 13; in original form 2020 August 24 ABSTRACT PHANGS-HST is an ultraviolet-optical imaging survey of 38 spiral galaxies within ∼20 Mpc. Combined with the PHANGS- ALMA, PHANGS-MUSE surveys and other multiwavelength data, the data set will provide an unprecedented look into the connections between young stars, H II regions, and cold molecular gas in these nearby star-forming galaxies. Accurate distances are needed to transform measured observables into physical parameters (e.g. -
The Relationship Between Gas Content and Star Formation Rate in Spiral Galaxies
A&A 490, 571–581 (2008) Astronomy DOI: 10.1051/0004-6361:200810604 & c ESO 2008 Astrophysics The relationship between gas content and star formation rate in spiral galaxies. Comparing the local field with the Virgo cluster M. Fumagalli1,2 and G. Gavazzi1 1 Istituto di Fisica G. Occhialini, Universita’ di Milano-Bicocca, Piazza della scienza 3, Milano, Italy e-mail: [email protected] 2 Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USA e-mail: [email protected] Received 15 July 2008 / Accepted 1 August 2008 ABSTRACT Context. Despite many studies of star formation in spiral galaxies, a complete and coherent understanding of the physical processes that regulate the birth of stars has not yet been achieved, nor has unanymous consensus been reached, despite the many attempts, on the effects of the environment on the star formation in galaxy members of rich clusters. Aims. We focus on the local and global Schmidt law and we investigate how cluster galaxies have their star formation activity perturbed. Methods. We collect multifrequency imaging for a sample of spiral galaxies, members of the Virgo cluster and of the local field; we compute the surface density profiles for the young and for the bulk of the stellar components, for the molecular and for the atomic gas. Results. Our analysis shows that the bulk of the star formation correlates with the molecular gas, but the atomic gas is important or even crucial in supporting the star formation activity in the outer part of the disks. Moreover, we show that cluster members that suffer from a moderate HI removal have their molecular component and their SFR quenched, while highly perturbed galaxies show an additional truncation in their star forming disks. -
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. -
May 2013 BRAS Newsletter
www.brastro.org May 2013 What's in this issue: PRESIDENT'S MESSAGE .............................................................................................................................. 2 NOTES FROM THE VICE PRESIDENT ........................................................................................................... 3 MESSAGE FROM THE HRPO ...................................................................................................................... 4 OBSERVING NOTES ..................................................................................................................................... 5 DEEP SKY OBJECTS ................................................................................................................................... 6 MAY ASTRONOMICAL EVENTS .................................................................................................................... 7 TREASURER’S NOTES ................................................................................................................................. 8 PREVIOUS MEETING MINUTES .................................................................................................................... 9 IMPORTANT NOTE: This month's meeting will be held on Saturday, May 18th at LIGO. PRESIDENT'S MESSAGE Hi Everyone, April was quite a busy month and the busiest day was International Astronomy Day. As you may have heard, we had the highest attendance at our Astronomy Day festivities at the HRPO ever. Approximately 770 people attended this year -
Classification of Galaxies Using Fractal Dimensions
UNLV Retrospective Theses & Dissertations 1-1-1999 Classification of galaxies using fractal dimensions Sandip G Thanki University of Nevada, Las Vegas Follow this and additional works at: https://digitalscholarship.unlv.edu/rtds Repository Citation Thanki, Sandip G, "Classification of galaxies using fractal dimensions" (1999). UNLV Retrospective Theses & Dissertations. 1050. http://dx.doi.org/10.25669/8msa-x9b8 This Thesis is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Thesis in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Thesis has been accepted for inclusion in UNLV Retrospective Theses & Dissertations by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. -
Arxiv:Astro-Ph/0305472 V1 23 May 2003
Astronomy & Astrophysics manuscript no. (will be inserted by hand later) An Hα survey aiming at the detection of extraplanar diffuse ionized gas in halos of edge–on spiral galaxies ? II. The Hα survey atlas and catalog J. Rossa ??1,2 and R.–J. Dettmar1 1 Astronomisches Institut, Ruhr–Universit¨at Bochum, D–44780 Bochum, Germany e-mail: [email protected], [email protected] 2 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, U.S.A. (present address) Received 14 February 2003 / Accepted 6 May 2003 Abstract. In this second paper on the investigation of extraplanar diffuse ionized gas in nearby edge–on spiral galaxies we present the actual results of the individual galaxies of our Hα imaging survey. A grand total of 74 galaxies have been studied, including the 9 galaxies of a recently studied sub–sample (Rossa & Dettmar 2000). 40.5% of all studied galaxies reveal extraplanar diffuse ionized gas, whereas in 59.5% of the survey galaxies no extraplanar diffuse ionized gas could be detected. The average distances of this extended emission above the galactic midplane range from 1–2 kpc, while individual filaments in a few galaxies reach distances of up to |z| ∼ 6 kpc. In several cases a pervasive layer of ionized gas was detected, similar to the Reynolds layer in our Milky Way, while other galaxies reveal only extended emission locally. The morphology of the diffuse ionized gas is discussed for each galaxy and is compared with observations of other important ISM constituents in the context of the disk–halo connection, in those cases where published results were available.