DOCSLIB.ORG

The $-12$ Mag Dip in the Galaxy Luminosity Function of Hickson

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The $-12$ Mag Dip in the Galaxy Luminosity Function of Hickson Draft version August 16, 2021 Typeset using LATEX twocolumn style in AASTeX63 The −12 mag dip in the galaxy luminosity function of Hickson Compact Groups∗ Hitomi Yamanoi,1, 2 Masafumi Yagi,2, 3 Yutaka Komiyama,2, 4 and Jin Koda5 1Center for Information and Communication Technology, Hitotsubashi University, 2-1 Naka, Kunitachi, Tokyo 186-8601, Japan 2Subaru Telescope, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan 3Department of Advanced Sciences, Hosei University, 3-7-2 Kajinocho, Koganei, Tokyo 184-8584, Japan 4Department of Astronomical Science, School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan 5Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800, USA (Received March 10, 2020; Revised June 29, 2020; Accepted July 1, 2020) Submitted to AJ ABSTRACT We present the galaxy luminosity functions (LFs) of four Hickson Compact Groups using image data from the Subaru Hyper Suprime-Cam. A distinct dip appeared in the faint-ends of all the LFs at Mg ∼ −12. A similar dip was observed in the LFs of the galaxy clusters Coma and Centaurus. However, LFs in the Virgo, Hydra, and the field had flatter slopes and no dips. As the relative velocities among galaxies are lower in compact groups than in clusters, the effect of galaxy-galaxy interactions would be more significant in compact groups. The Mg ∼ −12 dip of compact groups may imply that frequent galaxy-galaxy interactions would affect the evolution of galaxies, and the dip in LF could become a boundary between different galaxy populations. Keywords: galaxies: groups: individual (Hickson Compact Group) | galaxies: luminosity function, mass function | galaxies: dwarf 1. INTRODUCTION Faint-ends (M > −12) of the LFs were investigated The galaxy luminosity function (LF) is a powerful tool in the cluster regions in our local neighborhood. Tren- for describing the properties of galaxy density in various tham & Tully(2002) represented the faint-end slopes of environments. A comparison between various LFs pro- LFs down to MR = −10 in five different environments. vides clues to the environmental dependence of galaxy These slopes were not as steep as those of the theoret- formation and evolution. The LFs of galaxy clusters ical mass function obtained from the cold dark matter show a distinct upturn in the −18 < M < −16 magni- (CDM) model. Yamanoi et al.(2012) found a significant tude range (e.g., Binggeli et al. 1988; Yagi et al. 2002; dip of MR ∼ −13 in the LF of the Coma cluster and a Parolin et al. 2003; Popesso et al. 2005; Mercurio et al. steep slope at the faint-end of MR > −13. The Centau- 2006; Barkhouse et al. 2007; Rines & Geller 2008; Lan rus cluster LF of Chiboucas, & Mateo(2006) showed a et al. 2016), while the LFs in the field environments dip at −14 < MV < −13, and a sign of a dip was seen arXiv:2007.02493v1 [astro-ph.GA] 6 Jul 2020 have flatter slopes to the faint-end (e.g., Blanton et al. in the Fornax LF (Hilker et al. 2003). In contrast, the 2005). The upturn of M ∼ −18 indicates a division LFs of the Virgo (Trentham, & Hodgkin 2002; Saba- of dominant galaxies between giant and dwarf galaxies tini et al. 2003; Lieder et al. 2012; Ferrarese et al. 2016) (e.g., Binggeli et al. 1988; Ferguson, & Sandage 1991; and Hydra clusters (Yamanoi et al. 2007; Misgeld et al. Trentham, & Hodgkin 2002; de Lapparent et al. 2003). 2008) did not show such a dip. In a lower-density re- gion such as the loose groups, Trentham et al.(2005) provided a composite LF of the neighboring four galaxy Corresponding author: Hitomi Yamanoi groups within the Local Group towards MR ∼ −10, and [email protected] confirmed a weak dip of MR ∼ −11. The other result ∗ Based on data collected at Subaru Telescope, which is operated also indicated that some loose groups tend to show a by the National Astronomical Observatory of Japan. 2 Yamanoi et al. deficiency of galaxies at −12 < MV < −11 (M¨ulleret al. 2018). The faint-end dip may reflect the presence of physical processes in galaxy formation and/or evolution that are driven by environmental effects. A large sample of LFs in various environments is required to understand the origin of the faint-end dip. In this paper, we focus on compact groups, which have several giant galaxies con- centrated in a small region. Galaxy interactions would have a more significantly impact in compact groups than in galaxy clusters as the relative velocities of galaxies are smaller, and hence, the effective interaction timescales are longer, while interactions with hot gas would be weaker. Previous studies of the LFs of compact groups Figure 1. Completeness of extended objects as a function of g-band magnitude for each HCG image. The 90% com- are summarized in AppendixA. There are very few stud- pleteness is plotted as dashed line. HCG79 and HCG59 show ies of the LFs that cover the magnitude ranges fainter more than 90% completeness at mg < 24:7, while the 90% than M ∼ −12. To investigate the faint-end dip in com- completeness of HCG44 and HCG68 are down to mg ∼ 25. pact groups, we studied the faint-ends of LFs with deep images of compact groups selected from the catalog of scope and Rapid Response System 1 (Pan-STARRS1) Hickson Compact Groups (HCGs; Hickson 1982). were referred to as astrometric catalogs. We detected objects using SExtractor (Bertin, & 2. OBSERVATIONS Arnouts 1996) and adopted MAG AUTO for measuring the The HCG fields were observed with the Hyper magnitude, while excluding the saturated objects. The Suprime-Cam (HSC: Kawanomoto et al. 2018; Furusawa limiting magnitude of point sources was estimated by et al. 2018; Komiyama et al. 2018; Miyazaki et al. 2018) measuring sky counts with the 200-diameter aperture in mounted on the Subaru Telescope. The HSC uses 104 the reduced image. We applied the Gaussian fitting of science CCDs, which cover 1:5◦ field-of-view in diam- the histogram of sky counts and calculated the 5σ limit- eter with a pixel scale of 0:1700. The observation was ing magnitude, which resulted in ∼ 26 mag in each im- made in the queue mode on 2016 March 8 UT. The age (see Table1). We also estimated the detection com- seeing size (the full width at half maximum, FWHM) pleteness of extended sources, creating mock galaxies in was ∼ 0:800. Although the targets discussed in this pa- the magnitude range of 20.0 { 28.0 with the Image Re- per are only a part of all the targets of our project, duction and Analysis Facility (IRAF: Tody 1986, 1993) and the completion of the project depends on future ob- task gallist. We embedded these galaxies into the servations, we analyzed the first four fields that were object subtracted images, which were obtained as the obtained so far. The g-band images of the four fields SExtractor check images of -OBJECTS, using mkobjects. (HCG44, HCG59, HCG68, and HCG79) based on the The galaxies were measured using SExtractor, and the catalog by Hickson et al.(1992) were obtained. Their corresponding parameters were adjusted to be the same redshifts were found to be less than 0.015, and no other as the detecting threshold for real objects. We evalu- group or cluster is known around the redshifts in these ated the detection rates for every 0.25 magnitude bin fields. We summarize our targets in Table1. We referred for the mock galaxies on the entire field of view of the to the NASA/IPAC Extragalactic Database (NED) for HSC image. Figure1 indicates that a 90% complete- the redshift (z) and the distance modulus (m − M) cor- ness fraction was attained for the extended objects at rected to the cosmic microwave background reference mg = 24:7, which corresponds to Mg = −9:4 for the frame, as shown in Table1, with default cosmological most distant galaxy group (HCG79). No completeness −1 −1 parameters H0 = 73 km s Mpc ,Ωmatter = 0:27 correction was performed when we evaluated the LFs in and Ωvaccum = 0:73. We use the AB-magnitude system the > 90% completeness range. throughout this paper. The galactic extinctions in g-band (Ag) in Table1 obtained from NED were adopted when we converted 3. DATA REDUCTION magnitudes from the apparent to the absolute values. The g-band images were reduced using HSC Pipeline (Bosch et al. 2018) version 4.0.5. We used dome flats for flat fielding. The data of the Panoramic Survey Tele- 4. LUMINOSITY FUNCTION HCG LF 3 Table 1. Observed HCGs Field RA Dec z Exp. Times m − MAg mlim (5σ) (J2000.0) (J2000.0) (min) (mag) (mag) (mag) (1) (2) (3) (4) (5) (6) (7) (8) HCG44 10:20:45.5 +21:33:37 0.0057 78 31.8 0.09 26.0 HCG59 11:51:01.0 +12:25:59 0.0147 60 33.9 0.11 26.3 HCG68 13:55:42.4 +40:05:17 0.0086 60 32.8 0.04 26.2 HCG79 16:01:23.8 +20:37:11 0.0148 30 33.9 0.21 26.1 In order to estimate the number of member galaxies, ten negative after background subtraction. This sug- we used the statistical background subtraction method gests a statistically significant deficit in group members (Bernstein et al. 1995). Our HSC image has a field of around this magnitude. In order to construct the to- view of ∼ 1:5◦ in diameter and is wide enough to cover tal of the LFs of all the HCGs, we first converted the both the HCG and its outer regions.
Load more

Recommended publications
  • Hubble Space Telescope Images of Stephan's Quintet
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server Hubble Space Telescope Images of Stephan's Quintet: Star Cluster Formation in a Compact Group Environment1;2 Sarah C. Gallagher, Jane C. Charlton3, Sally D. Hunsberger Department of Astronomy and Astrophysics The Pennsylvania State University University Park PA 16802 gallsc, charlton, [email protected] Dennis Zaritsky Steward Observatory University of Arizona Tucson, AZ 85721 [email protected] and Bradley C. Whitmore Space Telescope Science Institute 3700 San Martin Drive Baltimore, MD 21218 [email protected] ABSTRACT Analysis of Hubble Space Telescope/Wide Field Planetary Camera 2 images of Stephan’s Quintet, Hickson Compact Group 92, yielded 115 candidate star clusters (with V I<1:5). Unlike in merger remants, the cluster candidates in Stephan’s Quintet are not clustered in the inner− regions of the galaxies; they are spread over the debris and surrounding area. Specifically, these sources are located in the long sweeping tail and spiral arms of NGC 7319, in the tidal debris of NGC 7318B/A, and in the intragroup starburst region north of these galaxies. Analysis of the colors of the clusters indicate several distinct epochs of star formation that appear to trace the complex history of dynamical interactions in this compact group. Subject headings: galaxies: interactions | galaxies: individual (NGC 7318A, NGC 7318B, NGC 7319) | galaxies: star clusters | intergalactic medium 1. Introduction the central regions of mergers (Holtzman et al. 1992; Whitmore et al. 1993; Schweizer et al. 1996; Miller et al. The interactions of galaxies trigger bursts of star for- 1997; Whitmore et al.
    [Show full text]
  • Existence and Importance of Magnetic Fields in Tight Pairs and Groups of Galaxies 15 3 Summary of the Published Articles 17 3.1
    EXISTENCEANDIMPORTANCEOFMAGNETICFIELDSIN TIGHTPAIRSANDGROUPSOFGALAXIES błazej˙ nikiel-wroczynski´ A PhD thesis written under the supervision of Professor Marek Urbanik and co-supervision of Doctor Marek Jamrozy Astronomical Observatory Faculty of Physics, Astronomy and Applied Computer Science Jagiellonian University June 2015 Błazej˙ Nikiel-Wroczy´nski: Existence and importance of magnetic fields in tight pairs and groups of galaxies, © June 2015 supervisors: Prof. dr hab. Marek Urbanik Dr Marek Jamrozy alma mater: Jagiellonian University, Faculty of Physics, Astronomy and Applied Computer Science Dedication This work is dedicated to Rugia for being (probably unknowingly) an Earth-based analogue of the MHD dynamo, that amplified my determination to collect all the presented articles into one thesis, transferring the kinetic energy of my turbulent movements into a genuinely regular (not just anisotropic), scientific dissertation. ABSTRACT This dissertation is an attempt to investigate the existence and role of the intergalactic magnetic fields in compact groups and tight pairs of galaxies. Radio emission from several, well known objects of these types is analysed and properties of the discovered intergalactic mag- netised structures are discussed. Together, these results are used to show that wherever found, intergalactic magnetic fields play impor- tant role in the galactic dynamics and evolution. Non-thermal, in- tergalactic radio emission, which signifies existence of the magnetic fields, can be used as a very sensitive tracer of interactions and gas flows. Unusual magnetised objects and structures can be found in the intergalactic space, and their studies open a possibility to discover more about the cosmic magnetism itself. v PUBLICATIONS This dissertation has been written as a summary of the scientific ac- tivities previously reported in these articles: • Nikiel-Wroczy ´nski,B., Jamrozy, M., Soida, M., Urbanik, M., Multiwavelength study of the radio emission from a tight galaxy pair Arp 143, 2014, MNRAS, 444, 1729 • Nikiel-Wroczy ´nski,B., Soida, M., Bomans, D.
    [Show full text]
  • Paired and Interacting Galaxies: Conference Summary
    1- PAIRED AND INTERACTING GALAXIES: CONFERENCE SUMMARY Colin A. Norman Department of Physics and Astronomy, Johns Hopkins University and Space Telescope Science Institute 1. INTRODUCTION This has been an excellent conference with a very international component and a rich and wide ranging diversity of views on the topical subject of paired and interacting galaxies. The southern hospitality shown to us by our hosts Jack Sulentic and Bill Keel has been most gracious and the general growth of the astronomy group at the University of Alabama is most impressive. The conference began with the presentation of the basic data sets on pairs, groups, and interacting galaxies with the latter being further discussed with respect to both global properties and properties of the galactic nuclei. Then followed the theory, modelling and interpretation us- ing analytic techniques, simula+tionsand general modelling for spirals and ellipticals, starbursts and active galactic nuclei. Before the conference I had written down the three questions concern- ing pairs, groups and interacting galaxies that I hoped would be answered at the meeting: (1) How do they form? including the role of initial conditions, the importance of subclustering, the evolution of groups to compact groups, and the fate of compact groups;’(2) How do they evolve? including issues such as relevant timescales, the role of halos and the problem of overmerging, the triggering and enhancement of star formation and activity in the galactic nuclei, and the relative importance of dwarf versus giant encounters; and (3) Are they important? including the frequency of pairs and interactions, whether merging and interactions are very important aspects of the life of a normal galaxy at formation, during its evolution, in forming bars, shells, rings, bulges etc., and in the formation and evolution of active galaxies.
    [Show full text]
  • Image: NASA's Hubble Looks at a Members-Only Galaxy Club
    Image: NASA's Hubble looks at a members- only galaxy club 16 December 2013 destructive tendencies. The group members interact, circling and pulling at one another until they eventually merge together, signaling the death of the group, and the birth of a large galaxy. Provided by NASA Credit: European Space Agency (Phys.org) —This new Hubble image shows a handful of galaxies in the constellation of Eridanus (The River). NGC 1190, shown here on the right of the frame, stands apart from the rest; it belongs to an exclusive club known as Hickson Compact Group 22 (HCG 22). There are four other members of this group, all of which lie out of frame: NGC 1189, NGC 1191, NGC 1192, and NGC 1199. The other galaxies shown here are nearby galaxies 2MASS J03032308-1539079 (center), and dCAZ94 HCG 22-21 (left), both of which are not part of HCG 22. Hickson Compact Groups are incredibly tightly bound groups of galaxies. Their discoverer Paul Hickson observed only 100 of these objects, which he described in his HCG catalog in the 1980s. To earn the Hickson Compact Group label, there must be at least four members—each one fairly bright and compact. These short-lived groups are thought to end their lives as giant elliptical galaxies, but despite knowing much about their form and destiny, the role of compact galaxy groups in galactic formation and evolution is still unclear. These groups are interesting partly for their self- 1 / 2 APA citation: Image: NASA's Hubble looks at a members-only galaxy club (2013, December 16) retrieved 28 September 2021 from https://phys.org/news/2013-12-image-nasa-hubble-members-only- galaxy.html This document is subject to copyright.
    [Show full text]
  • Chandrals First Decade of Discovery
    SPECIAL FEATURE: INTRODUCTION Chandra’s first decade of discovery Douglas A. Swartza,1, Scott J. Wolkb, and Antonella Fruscioneb aUniversities Space Research Association, National Aeronautics and Space Administration Marshall Space Flight Center, Huntsville, AL 35805; and bHarvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 Edited by Harvey D. Tananbaum, Smithsonian Astrophysical Observatory, Cambridge, MA, and approved February 4, 2010 (received for review December 16, 2009) We review some of the many scientific results reported at a symposium held in September 2009 celebrating the 10th anniversary of National Aeronautics and Space Administration’s (NASA’s) Chandra X-ray Observatory. These results were contributed by scientists who were among the more than 300 symposium participants. We highlight those results that most emphasize the unique imaging and spectroscopic capabilities of Chandra. review | X-rays fter many years in the making regions of cosmic ray acceleration. Inves- Compact Objects (1), the Chandra X-ray Obser- tigators can also take advantage of the A SNR often contain central compact A vatory, one of the National strong broad emission lines from SNR to objects (CCOs). These are thought to be Aeronautics and Space Admin- perform spatially resolved spectroscopy neutron stars formed in the core collapse istration’s Great Observatories, was de- with Chandra and, thereby, map the dis- supernova explosions of massive stars. ployed by the STS-93 crew of the space tribution and measure the mass of the These stars are often just tiny dots em- shuttle Columbia on July 23, 1999. abundant elements from C to Fe in the bedded in the extensive X-ray glow of their Chandra’sofficial first light image was re- ejecta.
    [Show full text]
  • Joint Meeting of the American Astronomical Society & The
    American Association of Physics Teachers Joint Meeting of the American Astronomical Society & Joint Meeting of the American Astronomical Society & the 5-10 January 2007 / Seattle, Washington Final Program FIRST CLASS US POSTAGE PAID PERMIT NO 1725 WASHINGTON DC 2000 Florida Ave., NW Suite 400 Washington, DC 20009-1231 MEETING PROGRAM 2007 AAS/AAPT Joint Meeting 5-10 January 2007 Washington State Convention and Trade Center Seattle, WA IN GRATITUDE .....2 Th e 209th Meeting of the American Astronomical Society and the 2007 FOR FURTHER Winter Meeting of the American INFORMATION ..... 5 Association of Physics Teachers are being held jointly at Washington State PLEASE NOTE ....... 6 Convention and Trade Center, 5-10 January 2007, Seattle, Washington. EXHIBITS .............. 8 Th e AAS Historical Astronomy Divi- MEETING sion and the AAS High Energy Astro- REGISTRATION .. 11 physics Division are also meeting in LOCATION AND conjuction with the AAS/AAPT. LODGING ............ 12 Washington State Convention and FRIDAY ................ 44 Trade Center 7th and Pike Streets SATURDAY .......... 52 Seattle, WA AV EQUIPMENT . 58 SUNDAY ............... 67 AAS MONDAY ........... 144 2000 Florida Ave., NW, Suite 400, Washington, DC 20009-1231 TUESDAY ........... 241 202-328-2010, fax: 202-234-2560, [email protected], www.aas.org WEDNESDAY..... 321 AAPT AUTHOR One Physics Ellipse INDEX ................ 366 College Park, MD 20740-3845 301-209-3300, fax: 301-209-0845 [email protected], www.aapt.org Acknowledgements Acknowledgements IN GRATITUDE AAS Council Sponsors Craig Wheeler U. Texas President (6/2006-6/2008) Ball Aerospace Bob Kirshner CfA Past-President John Wiley and Sons, Inc. (6/2006-6/2007) Wallace Sargent Caltech Vice-President National Academies (6/2004-6/2007) Northrup Grumman Paul Vanden Bout NRAO Vice-President (6/2005-6/2008) PASCO Robert W.
    [Show full text]
  • Space Based Astronomy
    * Space Based Atronomy.b/w 2/28/01 8:53 AM Page C1 Educational Product National Aeronautics Educators Grades 5–8 and Space Administration EG-2001-01-122-HQ Space-Based ANAstronomy EDUCATOR GUIDE WITH ACTIVITIES FOR SCIENCE, MATHEMATICS, AND TECHNOLOGY EDUCATION * Space Based Atronomy.b/w 2/28/01 8:54 AM Page C2 Space-Based Astronomy—An Educator Guide with Activities for Science, Mathematics, and Technology Education is available in electronic format through NASA Spacelink—one of the Agency’s electronic resources specifically developed for use by the educa- tional community. The system may be accessed at the following address: http://spacelink.nasa.gov * Space Based Atronomy.b/w 2/28/01 8:54 AM Page i Space-Based ANAstronomy EDUCATOR GUIDE WITH ACTIVITIES FOR SCIENCE, MATHEMATICS, AND TECHNOLOGY EDUCATION NATIONAL AERONAUTICS AND SPACE ADMINISTRATION | OFFICE OF HUMAN RESOURCES AND EDUCATION | EDUCATION DIVISION | OFFICE OF SPACE SCIENCE This publication is in the Public Domain and is not protected by copyright. Permission is not required for duplication. EG-2001-01-122-HQ * Space Based Atronomy.b/w 2/28/01 8:54 AM Page ii About the Cover Images 1. 2. 3. 4. 5. 6. 1. EIT 304Å image captures a sweeping prominence—huge clouds of relatively cool dense plasma suspended in the Sun’s hot, thin corona. At times, they can erupt, escaping the Sun’s atmosphere. Emission in this spectral line shows the upper chro- mosphere at a temperature of about 60,000 degrees K. Source/Credits: Solar & Heliospheric Observatory (SOHO). SOHO is a project of international cooperation between ESA and NASA.
    [Show full text]
  • UNIVERSITY of CALIFORNIA SAN DIEGO the Impact of Stellar
    UNIVERSITY OF CALIFORNIA SAN DIEGO The impact of stellar feedback on galaxies and dark matter halos A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Physics by Tsang Keung Chan Committee in charge: Professor Dusan Keres, Chair Professor Patrick Diamond Professor George Fuller Professor Philip E. Gill Professor Michael Norman 2019 Copyright Tsang Keung Chan, 2019 All rights reserved. The dissertation of Tsang Keung Chan is approved, and it is acceptable in quality and form for publication on microfilm and electronically: Chair University of California San Diego 2019 iii DEDICATION For my parents and my sisters. iv EPIGRAPH We do not ask for what useful purpose the birds do sing, for song is their pleasure since they were created for singing. Similarly, we ought not to ask why the human mind troubles to fathom the secrets of the heavens. The diversity of the phenomena of nature is so great and the treasures hidden in the heavens so rich precisely in order that the human mind shall never be lacking in fresh nourishment. —Johannes Kepler v TABLE OF CONTENTS Signature Page . iii Dedication . iv Epigraph . .v Table of Contents . vi List of Figures . ix List of Tables . xii List of Abbreviations . xiii Acknowledgements . xiv Vita ............................................. xvi Abstract of the Dissertation . xvii Chapter 1 General introduction . .1 1.1 Stellar feedback . .1 1.1.1 The role of stellar feedback in Galaxy Formation Theory . .1 1.1.2 Dark matter halo structures . .5 1.1.3 Ultra Diffuse Galaxies . .7 1.1.4 Cosmic Rays and their effects on galaxies .
    [Show full text]
  • 12 Mag Dip in the Galaxy Luminosity Function of Hickson Compact Groups*
    The Astronomical Journal, 160:87 (8pp), 2020 August https://doi.org/10.3847/1538-3881/aba1ee © 2020. The American Astronomical Society. All rights reserved. The −12 mag Dip in the Galaxy Luminosity Function of Hickson Compact Groups* Hitomi Yamanoi1,2, Masafumi Yagi2,3 , Yutaka Komiyama2,4 , and Jin Koda5 1 Center for Information and Communication Technology, Hitotsubashi University, 2-1 Naka, Kunitachi, Tokyo 186-8601, Japan; [email protected] 2 Subaru Telescope, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan 3 Department of Advanced Sciences, Hosei University, 3-7-2 Kajinocho, Koganei, Tokyo 184-8584, Japan 4 Department of Astronomical Science, School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan 5 Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800, USA Received 2020 March 10; revised 2020 June 29; accepted 2020 July 1; published 2020 July 30 Abstract We present the galaxy luminosity functions (LFs) of four Hickson Compact Groups using image data from the Subaru Hyper Suprime-Cam. A distinct dip appeared in the faint ends of all the LFs at Mg∼−12. A similar dip was observed in the LFs of the galaxy clusters Coma and Centaurus. However, LFs in the Virgo, Hydra, and the field had flatter slopes and no dips. As the relative velocities among galaxies are lower in compact groups than in clusters, the effect of galaxy–galaxy interactions would be more significant in compact groups. The Mg∼−12 dip of compact groups may imply that frequent galaxy–galaxy interactions would affect the evolution of galaxies, and the dip in LF could become a boundary between different galaxy populations.
    [Show full text]
  • Turbulence in Hickson Compact Group NGC 7674
    The Astrophysical Journal, 893:26 (13pp), 2020 April 10 https://doi.org/10.3847/1538-4357/ab77ae © 2020. The American Astronomical Society. All rights reserved. Spinning Bar and a Star-formation Inefficient Repertoire: Turbulence in Hickson Compact Group NGC 7674 Diane M. Salim1,2 , Katherine Alatalo3,4,5 , Christoph Federrath1,2 , Brent Groves1,2 , and Lisa J. Kewley1,2 1 Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia; [email protected] 2 ARC Centre Of Excellence For All Sky Astrophysics in 3D (ASTRO3D), Australia 3 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA 4 The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101, USA 5 Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA Received 2019 July 3; revised 2020 February 3; accepted 2020 February 9; published 2020 April 9 Abstract The physics regulating star formation (SF) in Hickson Compact Groups (HCG) has thus far been difficult to describe, due to their unique kinematic properties. In this study, we expand upon previous works to devise a more physically meaningful SF relation able to better encompass the physics of these unique systems. We combine CO(1–0) data from the Combined Array from Research in Millimeter Astronomy to trace the column density of molecular gas Sgas and deep Hα imaging taken on the Southern Astrophysical Research Telescope tracing SSFR to investigate SF efficiency across face-on HCG, NGC 7674. We find a lack of universality in SF, with two distinct sequences present in the Sgas–SSFR plane; one for inside and one for outside the nucleus.
    [Show full text]
  • THE SURVEY for IONIZATION in NEUTRAL GAS GALAXIES. I. DESCRIPTION and INITIAL RESULTS Gerhardt R
    The Astrophysical Journal Supplement Series, 165:307–337, 2006 July A # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE SURVEY FOR IONIZATION IN NEUTRAL GAS GALAXIES. I. DESCRIPTION AND INITIAL RESULTS Gerhardt R. Meurer,1 D. J. Hanish,1 H. C. Ferguson,2 P. M. Knezek,3 V. A. Kilborn,4,5 M. E. Putman,6 R. C. Smith,7 B. Koribalski,5 M. Meyer,2 M. S. Oey,6 E. V. Ryan-Weber,8 M. A. Zwaan,9 T. M. Heckman,1 R. C. Kennicutt, Jr.,10 J. C. Lee,10 R. L. Webster,11 J. Bland-Hawthorn,12 M. A. Dopita,13 K. C. Freeman,13 M. T. Doyle,14 M. J. Drinkwater,14 L. Staveley-Smith,5 and J. Werk6 Received 2005 August 1; accepted 2006 February 6 ABSTRACT We introduce the Survey for Ionization in Neutral Gas Galaxies (SINGG), a census of star formation in H i– selected galaxies. The survey consists of H and R-band imaging of a sample of 468 galaxies selected from the H i Parkes All Sky Survey (HIPASS). The sample spans three decades in H i mass and is free of many of the biases that affect other star-forming galaxy samples. We present the criteria for sample selection, list the entire sample, discuss our observational techniques, and describe the data reduction and calibration methods. This paper focuses on 93 SINGG targets whose observations have been fully reduced and analyzed to date. The majority of these show a single emission line galaxy (ELG). We see multiple ELGs in 13 fields, with up to four ELGs in a single field.
    [Show full text]
  • Isolated Elliptical Galaxies
    Isolated Elliptical Galaxies Fatma Mohamed Reda Mahmoud Mohamed (M.Sc.) A thesis presented in fulfilment of the requirements of Doctor of Philosophy. Faculty of Information and Communication Technology Swinburne University of Technology 2007 Abstract This thesis presents a detailed study of a well defined sample of isolated early-type galaxies. We define a sample of 36 nearby isolated early-type galaxies using a strict isolation criteria. New wide-field optical imaging of 20 isolated galaxies confirms their early-type morphology and relative isolation. We find that the isolated galaxies reveal a colour-magnitude relation similar to cluster ellipticals, which suggests that they formed at a similar epoch to cluster galaxies, such that the bulk of their stars are very old. However, several galaxies of our sample reveal evidence for dust lanes, plumes, shells, boxy and disk isophotes. Thus at least some isolated galaxies have experienced a recent merger/accretion event which may have also induced a small burst of star formation. Using new long-slit spectra of 12 galaxies we found that, isolated galaxies follow similar scaling relations between central stellar population parameters, such as age, metallicity [Z/H] and α-element abundance [E/Fe], with galaxy velocity dispersion to their counterparts in high density environments. However, isolated galaxies tend to have slightly younger ages, higher metallicities and lower abundance ratios. Such properties imply an extended star formation history for galaxies in lower density environments. We measure age gradients that anticorrelate with the central galaxy age. Thus as a young starburst evolves, the age gradient flattens from positive to almost zero.
    [Show full text]