DOCSLIB.ORG

Surface Photometry of Early-Type Galaxies in Rich Clusters

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Surface Photometry of Early-Type Galaxies in Rich Clusters Durham E-Theses Surface photometry of early-type galaxies in rich clusters Steel, James How to cite: Steel, James (1998) Surface photometry of early-type galaxies in rich clusters, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/4868/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk Surface Photometry of Early-Type Galaxies in Rich Clusters James Steel A thesis submitted to the University of Durham in accordance with the regulations for admittance to the Degree of Doctor of Philosophy. The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. Department of Physics University of Durham August 1998 f he copyright of this thesis rests with the author. No quotation from it should be published without the written consent of the author an information derived from it should be acknowledged. AUG 1999 Preface The work described in this thesis was undertaken between 1992 and 1997 whilst the au• thor was a research student under the supervision of Dr. J.R. Lucey in the Department of Physics at the University of Durham. This work has not been submitted for any other degree at the University of Durham or at any other University. The work contained in this thesis is entirely the authors own work (the observing run at the Isaac Newton Telescope, La Palma, in March 1994, was carried out in collaboration with John Lucey and Dave Carter). It is expected that some of the work contained in this thesis will be published in the scientific press during 1998. Acknowledgements I would first and foremost like to thank my supervisor. Dr. John Lucey, for all his support, encouragement and patience over the past five years. The past year has been pretty stress• ful as I have struggled with holding down a full-time job and completing this thesis - John's comments and suggestions regarding the thesis have always been very helpful and much appreciated. I'd also like to thank the colleagues which I have collaborated with on various projects over the past years, including Rafael Guzman, Russell Smith, Mike Hudson and Roger Davies. The STARLINK computing facilities at Durham have improved continuously during my time here, and I thank Alan Lotts for his vital work maintaining the system which we all rely on. An important part of thesis has been the measurement of surface photometry, and I'd like to thank Marjin Franx for his permission to use the GALPHOT ellipse-fitting program. I acknowledge the support given to me by a SERC/PPARC stu• dentship during my first three years in Durham. A special thanks goes to all the colleagues who have had the grave misfortune of shar• ing an office with me! I hope I've remembered everyone: Luis Teodoro, Rafael Guzman, Ian Small, Jeremy Heyl, Vince Eke, Henry McCracken, Russell Smith, Andrew Ratcliffe, Scott Groom, Doug Burke, Glaire Halliday, Katherine Gunn, Eric Bell, Harald Kuntschner and Fiona Hoyle. Also the lucky ones who've never shared an office with me - Omar .Al- maini, Paul Young, Roger Haynes, Paul Alton and anyone else I've forgot! Outside the world of astronomy, I like to thank everyone at Durham University Hillwalking society for providing me with some much-needed light entertainment during my time in Durham - Saturday's are never going to be the same again! Finally, I'd like to thank my family in Yorkshire - Mum, Dad, Jonathan and Sid - for all their support over the long years while I have been a student in Leicester and Durham. James Steel 24th August 1998 Abstract This thesis investigates the morphology of early-type galaxies in two rich clusters using 2D surface photometry. In particular, the amount of light in the 'disk' component is focussed upon, as the presence of a disk is the main morphological criterion in distinguishing between the traditional 'elliptical' and 'SO' classes. Extensive and photometric i?-band CCD observations of continuous areas of the Coma and Abell 1367 clusters were obtained at the 2.5 m Isaac Newton telescope, La Palma during March 1994. A subset of this large data-set has been used in this study, comprising a magnitude-limited (to R = 15.6) sample of 153 galaxies in the two clusters. Surface photometry measurements, including surface brightness profiles and isophotal shapes, have been made for the sample. Atmospheric seeing is a major problem when measuring light profiles at the distance of Coma from ground-based telescopes. Typical seeing at La Palma {FWHM^l.2") is a significant fraction of the efi"ective radius of many Coma/Abell 1367 galaxies (re~3" for small eUipticals). An iterative algorithm was devel• oped to deconvolve the effects of seeing from surface brightness profiles. The result of the algorithm is to extend the range of useful surface photometry inwards to within 2 times the FWHM. In order to parametrise the surface brightness profiles and discriminate be• tween different profile-types, further software was developed to fit one- and two-component model profiles to the seeing-corrected data. The following parameters were measured and tabulated for each of the 153 galaxies: total magnitude Mt] half-light parameters ri/2 and (/i)j^2! 3B at half-light radius //(ri/2); photometric diameter Z^i9.23 (equivalent to Z7„); eUipticity at /? = 21.5 isophote £21.5; averaged isophote high-order terms (C3), (53), (C4) and (54); effective radii and surface brightnesses of 5 single power-law rn models, r"e and (n = 1,2,3,4,5); best-fitting power-law index n\ bulge effective radii and surface brightnesses from the two-component fit r^e and (/i) ^\ disk effective parameters r'^e and {nY^] and disk-to-bulge luminosity ratio DjB. The measured parameters have been used to investigate various aspects of early-type galaxy morphology. The conclusions are outlined below. Firstly, a two-component plus exponential model is a better fit to most galaxies than a single component law fit. Secondly, the traditional division of early-type galaxies into 'elliptical' and 'SO' classes is severely biased by the viewing angle. In fact, it appears that early-type galaxies comprise a population of objects with smoothly varying bulge-to-disk ratio - although a few ellipticals (less than 13%) do not appear to have a exponential component. Finally, there is a gen• eral correlation (with much scatter) between the size and the profile shapes of early-type galaxies. The interpretation is that smaller galaxies are more disk-dominated than larger galaxies, which can be linked to the merging process in rich clusters. Contents Introduction - Early-type Galaxies in Clusters 4 1.1 Overview 4 1.2 Galaxy Morphology 5 1.3 The Cluster Environment 6 1.4 Causes of the Morphology-Density Relation 7 1.5 Early-type Galaxies - Surface Photometry 9 1.6 Aims of This Study 13 Sample and Observations 16 2.1 Observational Overview 16 2.2 Sample Selection - Coma (Abell 1656) 18 2.3 Sample Selection - Abell 1367 20 2.4 The Project Sample 24 Calibration and Preparation 28 3.1 Introduction 28 3.2 CCD Calibration - Biasing and Flat-fielding 28 3.2.1 Bias Removal 28 3.2.2 Flat-fielding 29 3.3 Photometric Calibration - Standard Stars 31 3.4 Data Preparation 36 Aperture Photometry and Total Magnitudes 42 4.1 Introduction 42 4.2 Elliptical Aperture Magnitudes 42 4.3 Magnitude Extrapolation 44 4.4 Global Parameters 46 4.5 Internal Comparisons 46 4.6 External Comparisons 48 4.7 Conclusion 59 Seeing Deconvolution 60 5.1 Introduction - Galaxy Profiles and Seeing 60 5.2 Image Restoration Methods 62 5.3 Surface Photometry Measurement 63 5.4 Profile Deconvolution 67 5.5 Examples using Synthetic Galaxy Models 76 5.6 Seeing Corrections and Aperture Photometry 97 CONTENTS 2 5.7 Conclusions 99 6 Parametrising the Surface Brightness Profile 100 6.1 Introduction 100 6.2 Fitting Single Power-law Profiles 101 6.3 Fitting a Two-component Profile 103 6.4 Testing the Profile Fitting 112 6.5 Inchnation Effects 121 6.6 Fitting a Seeing-Convolved Model 127 6.7 Conclusions 127 7 Results and Discussion 130 7.1 Introduction 130 7.2 Two-Component Fitting - Comparisons 130 7.3 The Missing SO Problem 135 7.4 Bulge-Disk Model versus Power-Law Model 140 7.5 Isophotal Shapes 154 8 Conclusions 158 References 163 A Tables of Photometric and Isophotal Parameters 167 B Aperture Photometry - Output 174 B.l Early-Type Galaxies - Coma 174 B.2 Late-Type Galaxies - Coma 206 B.3 Irregular or PecuHar Galaxies - Coma 213 B.4 Unclassified Galaxies - Coma 216 B.5 Early-Type Galaxies - Abell 1367 219 B.6 Late-Type Galaxies - Abell 1367 226 B. 7 Irregular or Peculiar Galaxies - Abell 1367 228 C Surface Photometry - Output 229 C.
Load more

Recommended publications
  • The MASSIVE Survey-VIII. Stellar Velocity Dispersion Profiles And
    MNRAS 000,1{17 (2017) Preprint 26 October 2017 Compiled using MNRAS LATEX style file v3.0 The MASSIVE Survey - VIII. Stellar Velocity Dispersion Profiles and Environmental Dependence of Early-Type Galaxies Melanie Veale,1;2? Chung-Pei Ma,1;2? Jenny E. Greene,3 Jens Thomas,4 John P. Blakeslee,5 Jonelle L. Walsh,6 Jennifer Ito1 1Department of Astronomy, University of California, Berkeley, CA 94720, USA 2Department of Physics, University of California, Berkeley, CA 94720, USA 3Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA 4Max Plank-Institute for Extraterrestrial Physics, Giessenbachstr. 1, D-85741 Garching, Germany 5Dominion Astrophysical Observatory, NRC Herzberg Astronomy & Astrophysics, Victoria BC V9E2E7, Canada 6George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, and Department of Physics and Astronomy, Texas A&M University, College Station, TX 77843, USA Accepted XXX. Received YYY; in original form ZZZ ABSTRACT We measure the radial profiles of the stellar velocity dispersions, σ¹Rº, for 90 early-type galaxies (ETGs) in the MASSIVE survey, a volume-limited integral-field spectroscopic (IFS) galaxy survey targeting all northern-sky ETGs with absolute K-band magnitude > 11 MK < −25:3 mag, or stellar mass M∗ ∼ 4 × 10 M , within 108 Mpc. Our wide-field 10700×10700 IFS data cover radii as large as 40 kpc, for which we quantify separately the inner (2 kpc) and outer (20 kpc) logarithmic slopes γinner and γouter of σ¹Rº. While γinner is mostly negative, of the 56 galaxies with sufficient radial coverage to determine γouter we find 36% to have rising outer dispersion profiles, 30% to be flat within the uncertainties, and 34% to be falling.
    [Show full text]
  • Hot Interstellar Matter in Elliptical Galaxies
    Hot Interstellar Matter in Elliptical Galaxies For further volumes: http://www.springer.com/series/5664 Astrophysics and Space Science Library EDITORIAL BOARD Chairman W. B. BURTON, National Radio Astronomy Observatory, Charlottesville, Virginia, U.S.A. ([email protected]); University of Leiden, The Netherlands ([email protected]) F. BERTOLA, University of Padua, Italy J. P. CASSINELLI, University of Wisconsin, Madison, U.S.A. C. J. CESARSKY, Commission for Atomic Energy, Saclay, France P. EHRENFREUND, Leiden University, The Netherlands O. ENGVOLD, University of Oslo, Norway A. HECK, Strasbourg Astronomical Observatory, France E. P. J. VAN DEN HEUVEL, University of Amsterdam, The Netherlands V. M. KASPI, McGill University, Montreal, Canada J. M. E. KUIJPERS, University of Nijmegen, The Netherlands H. VAN DER LAAN, University of Utrecht, The Netherlands P. G. MURDIN, Institute of Astronomy, Cambridge, UK F. PACINI, Istituto Astronomia Arcetri, Firenze, Italy V. RADHAKRISHNAN, Raman Research Institute, Bangalore, India B . V. S O M OV, Astronomical Institute, Moscow State University, Russia R. A. SUNYAEV, Space Research Institute, Moscow, Russia Dong-Woo Kim Silvia Pellegrini Editors Hot Interstellar Matter in Elliptical Galaxies 123 Editors Dong-Woo Kim Harvard Smithsonian Center for Astrophysics Garden Street 60 02138 Cambridge Massachusetts USA [email protected] Silvia Pellegrini Dipartimento di Astronomia Universita` di Bologna Via Ranzani 1 40127 Bologna Italy [email protected] Cover figure: Chandra image of NGC 7619. From Kim et al. (2008). Reproduced by permission of the AAS. ISSN 0067-0057 ISBN 978-1-4614-0579-5 e-ISBN 978-1-4614-0580-1 DOI 10.1007/978-1-4614-0580-1 Springer Heidelberg Dordrecht London New York Library of Congress Control Number: 2011938147 c Springer Science+Business Media, LLC 2012 This work is subject to copyright.
    [Show full text]
  • The Dynamical State of the Coma Cluster with XMM-Newton?
    A&A 400, 811–821 (2003) Astronomy DOI: 10.1051/0004-6361:20021911 & c ESO 2003 Astrophysics The dynamical state of the Coma cluster with XMM-Newton? D. M. Neumann1,D.H.Lumb2,G.W.Pratt1, and U. G. Briel3 1 CEA/DSM/DAPNIA Saclay, Service d’Astrophysique, L’Orme des Merisiers, Bˆat. 709, 91191 Gif-sur-Yvette, France 2 Science Payloads Technology Division, Research and Science Support Dept., ESTEC, Postbus 299 Keplerlaan 1, 2200AG Noordwijk, The Netherlands 3 Max-Planck Institut f¨ur extraterrestrische Physik, Giessenbachstr., 85740 Garching, Germany Received 19 June 2002 / Accepted 13 December 2002 Abstract. We present in this paper a substructure and spectroimaging study of the Coma cluster of galaxies based on XMM- Newton data. XMM-Newton performed a mosaic of observations of Coma to ensure a large coverage of the cluster. We add the different pointings together and fit elliptical beta-models to the data. We subtract the cluster models from the data and look for residuals, which can be interpreted as substructure. We find several significant structures: the well-known subgroup connected to NGC 4839 in the South-West of the cluster, and another substructure located between NGC 4839 and the centre of the Coma cluster. Constructing a hardness ratio image, which can be used as a temperature map, we see that in front of this new structure the temperature is significantly increased (higher or equal 10 keV). We interpret this temperature enhancement as the result of heating as this structure falls onto the Coma cluster. We furthermore reconfirm the filament-like structure South-East of the cluster centre.
    [Show full text]
  • Quantitative Morphology of Galaxies in the Core of the Coma Cluster
    To appear in Astrophys. Journal Quantitative Morphology of Galaxies in the Core of the Coma Cluster Carlos M. Guti´errez, Ignacio Trujillo1, Jose A. L. Aguerri Instituto de Astrof´ısica de Canarias, E-38205, La Laguna, Tenerife, Spain Alister W. Graham Department of Astronomy, University of Florida, Gainesville, Florida, USA and Nicola Caon Instituto de Astrof´ısica de Canarias, E-38205, La Laguna, Tenerife, Spain ABSTRACT We present a quantitative morphological analysis of 187 galaxies in a region covering the central 0.28 square degrees of the Coma cluster. Structural param- eters from the best-fitting S´ersic r1/n bulge plus, where appropriate, exponential disc model, are tabulated here. This sample is complete down to a magnitude of R=17 mag. By examining the Edwards et al. (2002) compilation of galaxy redshifts in the direction of Coma, we find that 163 of the 187 galaxies are Coma arXiv:astro-ph/0310527v1 19 Oct 2003 cluster members, and the rest are foreground and background objects. For the Coma cluster members, we have studied differences in the structural and kine- matic properties between early- and late-type galaxies, and between the dwarf and giant galaxies. Analysis of the elliptical galaxies reveals correlations among the structural parameters similar to those previously found in the Virgo and Fornax clusters. Comparing the structural properties of the Coma cluster disc galaxies with disc galaxies in the field, we find evidence for an environmental dependence: the scale lengths of the disc galaxies in Coma are 30% smaller. A kinematical analysis shows marginal differences between the velocity distri- butions of ellipticals with S´ersic index n < 2 (dwarfs) and those with n > 2 1Present address: Max–Planck–Institut f¨ur Astronomie, K¨onigstuhl 17, D–69117, Heidelberg, Germany –2– (giants); the dwarf galaxies having a greater (cluster) velocity dispersion.
    [Show full text]
  • Download (1MB)
    This is an Open Access document downloaded from ORCA, Cardiff University's institutional repository: http://orca.cf.ac.uk/136213/ This is the author’s version of a work that was submitted to / accepted for publication. Citation for final published version: Smith, Mark D., Bureau, Martin, Davis, Timothy A., Cappellari, Michele, Liu, Lijie, Onishi, Kyoko, Iguchi, Satoru, North, Eve V. and Sarzi, Marc 2021. WISDOM project - VI. Exploring the relation between supermassive black hole mass and galaxy rotation with molecular gas. Monthly Notices of the Royal Astronomical Society 500 , pp. 1933-1952. 10.1093/mnras/staa3274 file Publishers page: http://dx.doi.org/10.1093/mnras/staa3274 <http://dx.doi.org/10.1093/mnras/staa3274> Please note: Changes made as a result of publishing processes such as copy-editing, formatting and page numbers may not be reflected in this version. For the definitive version of this publication, please refer to the published source. You are advised to consult the publisher’s version if you wish to cite this paper. This version is being made available in accordance with publisher policies. See http://orca.cf.ac.uk/policies.html for usage policies. Copyright and moral rights for publications made available in ORCA are retained by the copyright holders. MNRAS 500, 1933–1952 (2021) doi:10.1093/mnras/staa3274 Advance Access publication 2020 October 22 WISDOM project – VI. Exploring the relation between supermassive black hole mass and galaxy rotation with molecular gas Mark D. Smith ,1‹ Martin Bureau,1,2 Timothy A. Davis ,3 Michele Cappellari ,1 Lijie Liu,1 Kyoko Onishi ,4,5,6 Satoru Iguchi ,5,6 Eve V.
    [Show full text]
  • Bright Star Double Variable Globular Open Cluster Planetary Bright Neb Dark Neb Reflection Neb Galaxy Int:Pec Compact Galaxy Gr
    bright star double variable globular open cluster planetary bright neb dark neb reflection neb galaxy int:pec compact galaxy group quasar ALL AND ANT APS AQL AQR ARA ARI AUR BOO CAE CAM CAP CAR CAS CEN CEP CET CHA CIR CMA CMI CNC COL COM CRA CRB CRT CRU CRV CVN CYG DEL DOR DRA EQU ERI FOR GEM GRU HER HOR HYA HYI IND LAC LEO LEP LIB LMI LUP LYN LYR MEN MIC MON MUS NOR OCT OPH ORI PAV PEG PER PHE PIC PSA PSC PUP PYX RET SCL SCO SCT SER1 SER2 SEX SGE SGR TAU TEL TRA TRI TUC UMA UMI VEL VIR VOL VUL Object ConRA Dec Mag z AbsMag Type Spect Filter Other names CFHQS J23291-0301 PSC 23h 29 8.3 - 3° 1 59.2 21.6 6.430 -29.5 Q ULAS J1319+0950 VIR 13h 19 11.3 + 9° 50 51.0 22.8 6.127 -24.4 Q I CFHQS J15096-1749 LIB 15h 9 41.8 -17° 49 27.1 23.1 6.120 -24.1 Q I FIRST J14276+3312 BOO 14h 27 38.5 +33° 12 41.0 22.1 6.120 -25.1 Q I SDSS J03035-0019 CET 3h 3 31.4 - 0° 19 12.0 23.9 6.070 -23.3 Q I SDSS J20541-0005 AQR 20h 54 6.4 - 0° 5 13.9 23.3 6.062 -23.9 Q I CFHQS J16413+3755 HER 16h 41 21.7 +37° 55 19.9 23.7 6.040 -23.3 Q I SDSS J11309+1824 LEO 11h 30 56.5 +18° 24 13.0 21.6 5.995 -28.2 Q SDSS J20567-0059 AQR 20h 56 44.5 - 0° 59 3.8 21.7 5.989 -27.9 Q SDSS J14102+1019 CET 14h 10 15.5 +10° 19 27.1 19.9 5.971 -30.6 Q SDSS J12497+0806 VIR 12h 49 42.9 + 8° 6 13.0 19.3 5.959 -31.3 Q SDSS J14111+1217 BOO 14h 11 11.3 +12° 17 37.0 23.8 5.930 -26.1 Q SDSS J13358+3533 CVN 13h 35 50.8 +35° 33 15.8 22.2 5.930 -27.6 Q SDSS J12485+2846 COM 12h 48 33.6 +28° 46 8.0 19.6 5.906 -30.7 Q SDSS J13199+1922 COM 13h 19 57.8 +19° 22 37.9 21.8 5.903 -27.5 Q SDSS J14484+1031 BOO
    [Show full text]
  • Spatially Resolved Spectroscopy of Coma Cluster Early–Type Galaxies
    ASTRONOMY & ASTROPHYSICS FEBRUARY I 2000, PAGE 449 SUPPLEMENT SERIES Astron. Astrophys. Suppl. Ser. 141, 449–468 (2000) Spatially resolved spectroscopy of Coma cluster early–type galaxies I. The database ? D. Mehlert1,2,??,???,????, R.P. Saglia1,R.Bender1,andG.Wegner3 1 Universit¨atssternwarte M¨unchen, 81679 M¨unchen, Germany 2 Present address: Landessternwarte Heidelberg, 69117 Heidelberg, Germany 3 Department of Physics and Astronomy, 6127 Wilder Laboratory, Dartmouth College, Hanover, NH 03755-3528, U.S.A. Received March 8; accepted September 30, 1999 Abstract. We present long slit spectra for a magnitude Key words: galaxies: elliptical and lenticular, cD; limited sample of 35 E and S0 galaxies of the Coma cluster. kinematics and dynamics; stellar content; abundances; The high quality of the data allowed us to derive spatially formation resolved spectra for a substantial sample of Coma galaxies for the first time. From these spectra we obtained rota- tion curves, the velocity dispersion profiles and the H3 and H4 coefficients of the Hermite decomposition of the 1. Introduction line of sight velocity distribution. Moreover, we derive the radial line index profiles of Mg, Fe and Hβ line indices This is the first of a series of papers aiming at investi- out to R ≈ 1re − 3re with high signal-to-noise ratio. We gating the stellar populations, the radial distribution and describe the galaxy sample, the observations and data re- the dynamics of early-type galaxies as a function of the duction, and present the spectroscopic database. Ground- environmental density. Spanning about 4 decades in den- based photometry for a subsample of 8 galaxies is also sity, the Coma cluster is the ideal place to perform such a presented.
    [Show full text]
  • THE GLOBULAR CLUSTER SYSTEM of the COMA CD GALAXY NGC 4874 from HUBBLE SPACE TELESCOPE ACS and WFC3/IR IMAGING* Hyejeon Cho1, John P
    The Astrophysical Journal, 822:95 (23pp), 2016 May 10 doi:10.3847/0004-637X/822/2/95 © 2016. The American Astronomical Society. All rights reserved. THE GLOBULAR CLUSTER SYSTEM OF THE COMA CD GALAXY NGC 4874 FROM HUBBLE SPACE TELESCOPE ACS AND WFC3/IR IMAGING* Hyejeon Cho1, John P. Blakeslee2, Ana L. Chies-Santos3,4, M. James Jee1, Joseph B. Jensen5, Eric W. Peng6,7, and Young-Wook Lee1 1 Department of Astronomy and Center for Galaxy Evolution Research, Yonsei University, Seoul 03722, Korea; [email protected], [email protected] 2 NRC Herzberg Astronomy & Astrophysics, Victoria, BC V9E 2E7, Canada; [email protected] 3 Departamento de Astronomia, Instituto de Física, UFRGS, Porto Alegre, R.S. 91501-970, Brazil 4 Departamento de Astronomia, IAGCA, Universidade de São Paulo, 05508-900 São Paulo, SP, Brazil 5 Department of Physics, Utah Valley University, Orem, Utah 84058, USA 6 Department of Astronomy, Peking University, Beijing 100871, China 7 Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China Received 2016 January 31; accepted 2016 April 4; published 2016 May 11 ABSTRACT We present new Hubble Space Telescope (HST) optical and near-infrared (NIR) photometry of the rich globular cluster (GC) system NGC 4874, the cD galaxy in the core of the Coma cluster (Abell 1656). NGC 4874 was observed with the HST Advanced Camera for Surveys in the F475W (g475) and F814W (I814) passbands and with the Wide Field Camera3 IR Channel in F160W (H160). The GCs in this field exhibit a bimodal optical color distribution with more than half of the GCs falling on the red side at g475−I814>1.
    [Show full text]
  • The Herschel Sprint PHOTO ILLUSTRATION: PATRICIA GILLIS-COPPOLA, HERSCHEL IMAGE: WIKIMEDIA S&T
    The Herschel Sprint PHOTO ILLUSTRATION: PATRICIA GILLIS-COPPOLA, HERSCHEL IMAGE: WIKIMEDIA S&T 34 April 2015 sky & telescope William Herschel’s Extraordinary Night of DiscoveryMark Bratton Recreating the legendary sweep of April 11, 1785 There’s little doubt that William Herschel was the most clearly with his instruments. As we will see, he did make signifi cant astronomer of the 18th century. His accom- occasional errors in interpretation, despite the superior plishments included the discovery of Uranus, infrared optics; for instance, he thought that the planetary nebula radiation, and four planetary satellites, as well as the M57 was a ring of stars. compilation of two extensive catalogues of double and The other factor contributing to Herschel’s interest multiple stars. His most lasting achievement, however, was the success of his sister, Caroline, in her study of the was his exhaustive search for undiscovered star clusters sky. He had built her a small telescope, encouraging her and nebulae, a key component in his quest to understand to search for double stars and comets. She located Messier what he called “the construction of the heavens.” In Her- objects and more, occasionally fi nding star clusters and schel’s time, astronomers were concerned principally with nebulae that had escaped the French astronomer’s eye. the study of solar system objects. The search for clusters Over the course of a year of observing, she discovered and nebulae was, up to that point, a haphazard aff air, with about a dozen star clusters and galaxies, occasionally not- a total of only 138 recorded by all the observers in history.
    [Show full text]
  • April 14 2018 7:00Pm at the April 2018 Herrett Center for Arts & Science College of Southern Idaho
    Snake River Skies The Newsletter of the Magic Valley Astronomical Society www.mvastro.org Membership Meeting President’s Message Tim Frazier Saturday, April 14th 2018 April 2018 7:00pm at the Herrett Center for Arts & Science College of Southern Idaho. It really is beginning to feel like spring. The weather is more moderate and there will be, hopefully, clearer skies. (I write this with some trepidation as I don’t want to jinx Public Star Party Follows at the it in a manner similar to buying new equipment will ensure at least two weeks of Centennial Observatory cloudy weather.) Along with the season comes some great spring viewing. Leo is high overhead in the early evening with its compliment of galaxies as is Coma Club Officers Berenices and Virgo with that dense cluster of extragalactic objects. Tim Frazier, President One of my first forays into the Coma-Virgo cluster was in the early 1960’s with my [email protected] new 4 ¼ inch f/10 reflector and my first star chart, the epoch 1960 version of Norton’s Star Atlas. I figured from the maps I couldn’t miss seeing something since Robert Mayer, Vice President there were so many so closely packed. That became the real problem as they all [email protected] appeared as fuzzy spots and the maps were not detailed enough to distinguish one galaxy from another. I still have that atlas as it was a precious Christmas gift from Gary Leavitt, Secretary my grandparents but now I use better maps, larger scopes and GOTO to make sure [email protected] it is M84 or M86.
    [Show full text]
  • Coma Cluster Object Populations Down to M R~-9.5
    Astronomy & Astrophysics manuscript no. astrophadami c ESO 2018 November 5, 2018 ⋆ Coma cluster object populations down to MR ∼ −9.5 C. Adami1, J.P. Picat2, F. Durret3,4, A. Mazure1, R. Pell´o2, and M. West5,6 1 LAM, Traverse du Siphon, 13012 Marseille, France 2 Observatoire Midi-Pyr´en´ees, 14 Av. Edouard Belin, 31400 Toulouse, France 3 Institut d’Astrophysique de Paris, CNRS, Universit´ePierre et Marie Curie, 98bis Bd Arago, 75014 Paris, France 4 Observatoire de Paris, LERMA, 61 Av. de l’Observatoire, 75014 Paris, France 5 Department of Physics and Astronomy, University of Hawaii, 200 West Kawili Street, LS2, Hilo HI 96720-4091, USA 6 Gemini Observatory, Casilla 603, La Serena, Chile Accepted . Received ; Draft printed: November 5, 2018 ABSTRACT Context. This study follows a recent analysis of the galaxy luminosity functions and colour-magnitude red sequences in the Coma cluster (Adami et al. 2007). Aims. We analyze here the distribution of very faint galaxies and globular clusters in an east-west strip of ∼ 42 × 7 arcmin2 crossing the Coma cluster center (hereafter the CS strip) down to the unprecedented faint absolute magnitude of MR ∼−9.5. Methods. This work is based on deep images obtained at the CFHT with the CFH12K camera in the B, R, and I bands. Results. The analysis shows that the observed properties strongly depend on the environment, and thus on the cluster history. When the CS is divided into four regions, the westernmost region appears poorly populated, while the regions around the brightest galaxies NGC 4874 and NGC 4889 (NGC 4874 and NGC 4889 being masked) are dominated by faint blue galaxies.
    [Show full text]
  • Radio Investigations of Clusters of Galaxies
    • • RADIO INVESTIGATIONS OF CLUSTERS OF GALAXIES a study of radio luminosity functions, wide-angle head-tailed radio galaxies and cluster radio haloes with the Westerbork Synthesis Radio Telescope proefschrift ter verkrijging van degraad van Doctor in de Wiskunde en Natuurwetenschappen aan de Rijksuniversiteit te Leiden, op gezag van de Rector Magnificus Or. D.J. Kuenen, hoogleraar in de Faculteit der Wiskunde en Natuurwetenschappen, volgens besluit van het College van Dekanen te verdedigen op woensdag 20 december 1978 teklokke 15.15 uur door Edwin Auguste Valentijn geboren te Voorburg in 1952 Sterrewacht Leiden 1978 elve/labor vincit - Leiden Promotor: Prof. Dr. H. van der Laan aan Josephine aan mijn ouders Cover: Some radio contours (1415 MHz) of the extended radio galaxies NGC6034, NGC6061 and 1B00+1SW2 superimposed to a smoothed galaxy distribution (number of galaxies per unit area, taken from Shane) of the Hercules Superoluster. The 90 % confidence error boxes of the Ariel VandUHURU observations of the X-ray source A1600+16 are also included. In the region of overlap of these two error boxes the position of a oD galaxy is indicated. The combined picture suggests inter-galactic material pervading the whole superaluster. CONTENTS CHAPTER 1 GENERAL INTRODUCTION AND SUMMARY 9 PART 1 OBSERVATIONS OF THE COI1A CLUSTER AT 610 MHZ 15 CHAPTER 2 COMA CLUSTER GALAXIES 17 Observation of the Coma Cluster at 610 MHz (Paper III, with W.J. Jaffe and G.C. Perola) I Introduction 17 II Observations 18 III Data Reduction 18 IV Radio Source Parameters 19 V Optical Data 20 VI The Radio Luminosity Function of the Coma Cluster Galaxies 21 a) LF of the (E+SO) Galaxies 23 b) LF of the (S+I) Galaxies 25 c) Radial Dependence of the LF 26 VII Other Properties of the Detected Cluster Galaxies 26 a) Spectral Indexes b) Emission Lines VIII The Central Radio Sources 27 a) 5C4.85 = NGC4874 27 b) 5C4.8I - NGC4869 28 c) Coma C 29 CHAPTER 3 RADIO SOURCES IN COMA NOT IDENTIFIED WITH CLUSTER GALAXIES 31 Radio Data and Identifications (Paper IV, with G.C.
    [Show full text]