Mapping Accreted Stars in Early-Type Galaxies Across the Mass-Size Plane

Total Page:16

File Type:pdf, Size:1020Kb

Mapping Accreted Stars in Early-Type Galaxies Across the Mass-Size Plane MNRAS 000,1– ?? (2021) Preprint 16 August 2021 Compiled using MNRAS LATEX style file v3.0 Mapping Accreted Stars in Early-Type Galaxies Across the Mass-Size Plane Thomas A. Davison,1,2¢ Mark A. Norris2, Ryan Leaman3,4, Harald Kuntschner1, Alina Boecker4, Glenn van de Ven3 1European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-87548 Garching bei Muenchen, Germany 2Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE, UK 3Department of Astrophysics, University of Vienna, Türkenschanzstraße 17, A-1180 Vienna, Austria 4Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany Accepted XXX. Received YYY; in original form ZZZ ABSTRACT Galaxy mergers are instrumental in dictating the final mass, structure, stellar populations, and kinematics of galaxies. Cosmo- logical galaxy simulations indicate that the most massive galaxies at z=0 are dominated by high fractions of ‘ex-situ’ stars, which formed first in distinct independent galaxies, and then subsequently merged into the host galaxy. Using spatially resolved MUSE spectroscopy we quantify and map the ex-situ stars in thirteen massive Early Type galaxies. We use full spectral fitting together with semi-analytic galaxy evolution models to isolate the signatures in the galaxies’ light which are indicative of ex-situ populations. Using the large MUSE field of view we find that all galaxies display an increase in ex-situ fraction with radius, with massive and more extended galaxies showing a more rapid increase in radial ex-situ fraction, (reaching values between ∼30% to 100% at 2 effective radii) compared to less massive and more compact sources (reaching between ∼5% to 40% ex-situ fraction within the same radius). These results are in line with predictions from theory and simulations which suggest ex-situ fractions should increase significantly with radius at fixed mass for the most massive galaxies. Key words: galaxies: elliptical and lenticular, cD – galaxies: evolution – galaxies: formation – galaxies: kinematics and dynamics – galaxies: stellar content 1 INTRODUCTION metallicity. GCs are found to display complex colour distributions in nearly every massive galaxy system studied (e.g. Zinn 1985; Larsen There are many indications from both observational and theoretical et al. 2001; Brodie & Strader 2006; Yoon et al. 2006; Peng et al. 2006; astrophysics that massive galaxies form ‘inside out’. This suggests Villaume et al. 2019; Fahrion et al. 2020). Red globular clusters are that galaxies begin as a core of stars formed in-situ, and grow larger thought to be closely linked to in-situ formation or very massive through both additional in-situ star formation and through the accre- mergers with higher metallicities, whereas their blue counterparts tion of smaller galaxies (Trujillo & Pohlen 2005; Auger et al. 2011; are more indicative of acquisition from lower mass galaxies with Pérez et al. 2013; Van Der Burg et al. 2015). As such, a gradient in lower metallicities. A result of this is that merging low-mass systems stellar population parameters can be imprinted on a galaxy, with the frequently provide GCs of low-metallicity, in stark contrast to in-situ largely in-situ core giving way to a more ex-situ dominated outskirts. metal rich GCs (Choksi et al. 2018; Forbes & Remus 2018). These Kinematic and population gradients have been found to exist fre- GC properties can be used to diagnose both merger history as well as quently in galaxies (e.g. Norris et al. 2006; Naab et al. 2009; Spolaor arXiv:2108.06160v1 [astro-ph.GA] 13 Aug 2021 gradients of ex-situ fraction (Forbes et al. 2015; Kruijssen et al. 2018; et al. 2010; Guérou et al. 2016; Sarzi, M. et al. 2018; Pinna, F. et al. Beasley et al. 2018; Mackey et al. 2019), however this is complicated 2019; Dolfi et al. 2020; Simons et al. 2020) however specific treat- by uncertain mappings between colour and metallicity, and uncertain ments to separate intrinsic gradients in the in-situ populations from ages of old GCs in systems outside the Local Group. those resulting from distributions of ex-situ material is a challenging task. This is largely a product of the difficulty in navigating around Further evidence of a two-phase galaxy assembly scenario is de- complex and interconnected secular processes that, additionally to rived from the faint stellar envelopes of massive galaxies. In Huang accretion, can provide gradients in stellar populations and kinemat- et al.(2018) (and building on work from Huang et al. 2013) the ics. As a result, disentangling the evidence of mergers is difficult to authors use deep imaging to study the stellar halos of around 7000 do via photometry, or from average metallicities and ages. massive galaxies from the Hyper Suprime-Cam (HSC) survey (Ai- Evidence of this two-phase galaxy assembly also comes in the hara et al. 2018) out to ¡100kpc. The authors find that surface mass form of bimodality of globular star clusters (GCs) in colour and density profiles show relative homogeneity within the central 10- 20kpc of the galaxies, however the scatter in this profile increases significantly with radius. Furthermore the authors find that the stellar ¢ E-mail: [email protected] halos become more prominent and more elliptical with increasing © 2021 The Authors 2 T. Davison et al. stellar mass. This is in line with a two-phase formation scenario in this is dependent on galaxy ‘class’ (with division based upon radial which central galaxy regions are formed by relatively stable in-situ stellar density profiles), see their figure 6 for detail. processes, and the outskirts are formed through far more stochastic Similarly in analyses of the EAGLE simulations (Schaye et al. accretion and so show a greater scatter in the surface mass density. 2015b; Crain et al. 2015), almost all galaxies are found to contain This is also found to be the case in Oyarzún et al.(2019) in which the a non-negligable quantity of accreted stellar mass (Davison et al. authors find a flattening in the metallicity profile of z<0.15 early type 2020). Clearly the influence of ex-situ populations from mergers and galaxies beyond a radius of 1.5r4, and conclude the most reasonable fly-bys on galaxy evolution is profound, influencing the composi- explanation of this is stellar accretion to the galaxy outskirts. This tion, kinematics and star formation mechanisms of a galaxy. Stellar result is also seen for samples of brightest cluster galaxies (Edwards material acquired in mergers has been shown to be the key con- et al. 2020) who likewise find signatures of the two-phase scenario tributor to stellar mass in massive galaxies. As shown in Davison 9 in profiles of kinematics and metallicity. et al.(2020), the lowest mass galaxies analysed (M ∗ ≈1×10 M ) Simulations of galaxy formation also show strong preferences for comprise of 10±5% ex-situ stars. This increases with mass up to the 12 galaxies to evolve through frequent mergers, and by accreting ma- most massive galaxies in the simulation (M∗ ≈2×10 M ) which terial to their outskirts (Kobayashi 2004; Zolotov et al. 2009; Oser are comprised of 80±9% ex-situ stars. Interestingly this work high- et al. 2010; Navarro-González et al. 2013; van der Wel et al. 2014; lighted trends in ex-situ fraction with galaxy density, showing that at Rodriguez-Gomez et al. 2016a). This is particularly clear for the most fixed mass more extended galaxies would on average contain higher massive ellipticals which show strong gradients of increasing ex-situ fractions of ex-situ stars. fraction with galactocentric radius, as well as high total fractions of With the recent advancement in integral field spectroscopy, galax- 12 ex-situ stars (with galaxies of mass M ¡ 1.7×10 M being com- ies are being studied spectroscopically as spatially resolved objects, posed of populations with an ex-situ fraction of ≈90%) (Oser et al. detailing spectral differences with galactocentric radius, and physical 2010; Lackner et al. 2012; Rodriguez-Gomez et al. 2016a; Pillepich location within a galaxy (see e.g. Guérou et al. 2016; Mentz et al. et al. 2018; Davison et al. 2020). Despite clear trends in ex-situ frac- 2016). Instruments such as SAURON at the WHT, GCMS (VIRUS- tion, these galaxies show a strong overlap between in- and ex-situ pop- P) on the 2.7m Harlan J. Smith telescope and MUSE (Multi-unit ulations within 2 effective radii (Pillepich et al. 2015) which causes spectroscopic explorer) at the VLT (Bacon et al. 2001; Hill et al. difficulty in photometric approaches to ex-situ population extraction 2008; Bacon et al. 2010) with their ∼1 arcminute field of views have (see also Remus & Forbes 2021). Modern photometric methods for been critical to the development of this field, and are a few of the identification of accreted stars and signatures of interaction (such as integral field units (IFUs) driving this particular area of research. tidal features) are able to accurately identify stellar features in the IFUs have significantly widened the field of galactic archaeology stellar halo (e.g. Duc et al. 2015; Morales et al. 2018; Martinez- for nearby galaxies as they have allowed for more thorough spatial Delgado et al. 2021a). Advanced deep-imaging methods can identify investigations of population distributions. Derived population maps features of interaction out to 10 effective radii (Jackson et al. 2021). can provide powerful insights into visual features, kinematics, and Despite these ongoing advances in treatments of photometric data, evolution (see e.g. Comerón et al. 2015; Faifer et al. 2017; Ge et al. most have difficulty accurately quantifying ex-situ fractions in the 2019; Davison et al. 2021). centres of galaxies (<2r4) especially for ancient mergers which have Alongside these advancements in instrumentation are equally im- largely diffused in projection space.
Recommended publications
  • Lateinischer Name: Deutscher Name: Hya Hydra Wasserschlange
    Lateinischer Name: Deutscher Name: Hya Hydra Wasserschlange Atlas Karte (2000.0) Kulmination um Cambridge 10, 16, Mitternacht: Star Atlas 17 12, 13, Sky Atlas Benachbarte Sternbilder: 20, 21 Ant Cnc Cen Crv Crt Leo Lib 9. Februar Lup Mon Pup Pyx Sex Vir Deklinationsbereic h: -35° ... 7° Fläche am Himmel: 1303° 2 Mythologie und Geschichte: Bei der nördlichen Wasserschlange überlagern sich zwei verschiedene Bilder aus der griechischen Mythologie. Das erste Bild zeugt von der eher harmlosen Wasserschlange aus der Geschichte des Raben : Der Rabe wurde von Apollon ausgesandt, um mit einem goldenen Becher frisches Quellwasser zu holen. Stattdessen tat sich dieser an Feigen gütlich und trug bei seiner Rückkehr die Wasserschlange in seinen Fängen, als angebliche Begründung für seine Verspätung. Um jedermann an diese Untat zu erinnern, wurden der Rabe samt Becher und Wasserschlange am Himmel zur Schau gestellt. Von einem ganz anderen Schlag war die Wasserschlange, mit der Herakles zu tun hatte: In einem Sumpf in der Nähe von Lerna, einem See und einer Stadt an der Küste von Argo, hauste ein unsagbar gefährliches und grässliches Untier. Diese Schlange soll mehrere Köpfe gehabt haben. Fünf sollen es gewesen sein, aber manche sprechen auch von sechs, neun, ja fünfzig oder hundert Köpfen, aber in jedem Falle war der Kopf in der Mitte unverwundbar. Fürchterlich war es, da diesen grässlichen Mäulern - ob die Schlange nun schlief oder wachte - ein fauliger Atem, ein Hauch entwich, dessen Gift tödlich war. Kaum schlug ein todesmutiger Mann dem Untier einen Kopf ab, wuchsen auf der Stelle zwei neue Häupter hervor, die noch furchterregender waren. Eurystheus, der König von Argos, beauftragte Herakles in seiner zweiten Aufgabe diese lernäische Wasserschlange zu töten.
    [Show full text]
  • Guide Du Ciel Profond
    Guide du ciel profond Olivier PETIT 8 mai 2004 2 Introduction hjjdfhgf ghjfghfd fg hdfjgdf gfdhfdk dfkgfd fghfkg fdkg fhdkg fkg kfghfhk Table des mati`eres I Objets par constellation 21 1 Androm`ede (And) Andromeda 23 1.1 Messier 31 (La grande Galaxie d'Androm`ede) . 25 1.2 Messier 32 . 27 1.3 Messier 110 . 29 1.4 NGC 404 . 31 1.5 NGC 752 . 33 1.6 NGC 891 . 35 1.7 NGC 7640 . 37 1.8 NGC 7662 (La boule de neige bleue) . 39 2 La Machine pneumatique (Ant) Antlia 41 2.1 NGC 2997 . 43 3 le Verseau (Aqr) Aquarius 45 3.1 Messier 2 . 47 3.2 Messier 72 . 49 3.3 Messier 73 . 51 3.4 NGC 7009 (La n¶ebuleuse Saturne) . 53 3.5 NGC 7293 (La n¶ebuleuse de l'h¶elice) . 56 3.6 NGC 7492 . 58 3.7 NGC 7606 . 60 3.8 Cederblad 211 (N¶ebuleuse de R Aquarii) . 62 4 l'Aigle (Aql) Aquila 63 4.1 NGC 6709 . 65 4.2 NGC 6741 . 67 4.3 NGC 6751 (La n¶ebuleuse de l’œil flou) . 69 4.4 NGC 6760 . 71 4.5 NGC 6781 (Le nid de l'Aigle ) . 73 TABLE DES MATIERES` 5 4.6 NGC 6790 . 75 4.7 NGC 6804 . 77 4.8 Barnard 142-143 (La tani`ere noire) . 79 5 le B¶elier (Ari) Aries 81 5.1 NGC 772 . 83 6 le Cocher (Aur) Auriga 85 6.1 Messier 36 . 87 6.2 Messier 37 . 89 6.3 Messier 38 .
    [Show full text]
  • The Dark Halo of the Hydra I Galaxy Cluster: Core, Cusp, Cosmological? ? Dynamics of NGC 3311 and Its Globular Cluster System
    Astronomy & Astrophysics manuscript no. N3311˙noletter˙V13˙astroph c ESO 2018 October 29, 2018 The dark halo of the Hydra I galaxy cluster: core, cusp, cosmological? ? Dynamics of NGC 3311 and its globular cluster system T. Richtler1, R. Salinas1;2, I. Misgeld3, M. Hilker4, G. K.T. Hau2, A.J. Romanowsky5, Y. Schuberth6, and M. Spolaor7 1 Departamento de Astronom´ıa, Universidad de Concepcion,´ Concepcion,´ Chile; [tom,rsalinas]@astro-udec.cl 2 European Southern Observatory, Alonso de Cordova´ 3107, Santiago, Chile 3 Sternwarte der Universitat¨ Munchen,¨ Scheinerstr.1, D-81679, Munchen,¨ Germany; [email protected] 4 European Southern Observatory, Karl-Schwarzschild-Str.2, Garching, Germany; [email protected] 5 UCO/Lick Observatory, University of California, Santa Cruz, CA 95064, USA; [email protected] 6 Argelander Institut fur¨ Astronomie, Auf dem Hugel¨ 71, 53121 Bonn, Germany; [email protected] 7 Australian Astronomical Observatory, PO Box 296, Epping, NSW 1710, Australia; [email protected] Received / Accepted ABSTRACT Context. Some galaxy clusters exhibit shallow or even cored dark matter density profiles in their central regions rather than the pre- dicted steep or cuspy profiles, conflicting with the standard understanding of dark matter. NGC 3311 is the central cD galaxy of the Hydra I cluster (Abell 1060). Aims. We use globular clusters around NGC 3311, combined with kinematical data of the galaxy itself, to investigate the dark matter distribution in the central region of Hydra I . Methods. Radial velocities of 118 bright globular clusters, based on VLT/VIMOS mask spectroscopy, are used to calculate velocity dispersions which are well defined out to 100 kpc.
    [Show full text]
  • TSP 2004 Telescope Observing Program
    THE TEXAS STAR PARTY 2004 TELESCOPE OBSERVING CLUB BY JOHN WAGONER TEXAS ASTRONOMICAL SOCIETY OF DALLAS RULES AND REGULATIONS Welcome to the Texas Star Party's Telescope Observing Club. The purpose of this club is not to test your observing skills by throwing the toughest objects at you that are hard to see under any conditions, but to give you an opportunity to observe 25 showcase objects under the ideal conditions of these pristine West Texas skies, thus displaying them to their best advantage. This year we have planned a program called “Starlight, Starbright”. The rules are simple. Just observe the 25 objects listed. That's it. Any size telescope can be used. All observations must be made at the Texas Star Party to qualify. All objects are within range of small (6”) to medium sized (10”) telescopes, and are available for observation between 10:00PM and 3:00AM any time during the TSP. Each person completing this list will receive an official Texas Star Party Telescope Observing Club lapel pin. These pins are not sold at the TSP and can only be acquired by completing the program, so wear them proudly. To receive your pin, turn in your observations to John Wagoner - TSP Observing Chairman any time during the Texas Star Party. I will be at the outside door leading into the TSP Meeting Hall each day between 1:00 PM and 2:30 PM. If you finish the list the last night of TSP, or I am not available to give you your pin, just mail your observations to me at 1409 Sequoia Dr., Plano, Tx.
    [Show full text]
  • Xlii Reunião Anual Da Sociedade Astronômica Brasileira
    XLII REUNIÃO ANUAL DA SOCIEDADE ASTRONÔMICA BRASILEIRA SÃO PAULO, 9 A 12 DE JULHO DE 2018 PROGRAMA OFICIAL Pal !"#a! $% A&'(")#(% F #$a$'% H $#(*& Ca#'%!% 'a U$(CS&l DIA 09 DE JULHO, SEGUNDA-FEIRA 09+00 , 12+00 Registro dos participantes e co oca!"o dos painéis 1-+00 , 1-+1. A$ert%ra da XLII Reunião An%a / l% P# !(' $" 'a SAB, Dr0 R ($al'% Ra1%! ' Ca#2al3%, / l% R ("%# 'a U$(CS&l, Dr0 L&4! H $#(*& A1a#al 'hair) *a ter J+ Macie (IAG.US/0 1-+1. , 15+1. 'onferência Con3idada - 4i3ian *(ite (AS/.USA) A!"#%$%16 7%# 2 #6 !"a8 + Ta9"(9! 7%# $8a8 1 $" "3#%&83%&" "3 /(/ l($ 15+1. , 15+-. 5e 6 Beatriz 4+ 9orres (UFSJ0 P#%: "% ' ;" $!<% =I$9l&!<% 'a! 1&l3 # ! $a! C(>$9(a! T 9$%l%8(a?+ a@A ! 2%l"a'a! /a#a a E'&9a@<% BB!(9a 15+-. , 15+.. Stephane 4+ *erner -IAG.US/0 A!"#%"&C #!+ &1a $%2a 7%#1a ' 7aD # '(2&l8a@<% 9( $"4E9a 15+.. , 1.+1. Edgar Inda ecio Smaniotto (Gr%p+Reg+Astron.,ar; ia0 O /a/ l '% G#&/% R 8(%$al ' A!"#%$%1(a ' Ma#4l(a FGRAMA) $a '(2&l8a@<% 'a a!"#%$%1(a 1 Ma#4l(a # 8(<% 1.+1. , 1H+20 Sess"o de Painéis e Ca1# 'hair) L%ci:ara Martins (NA9.UniCS% 0 1H+20 , 1H+50 U isses Barres de A meida -'7/F.,'9I'0 I C3 # $J%2 T l !9%/ A##a6 a$' "3 7&"&# %7 H(83,E$ #86 As"#%/36!(9! 1H+50 , 1K+00 Adriana 4a io ('RAAM.U/,0 S" lla# a9"(2("6 C6 !/%" "#a$!(" 1%' l($8 1K+00 , 1K+20 Diego Lorenzo-O i3eira (IAG.US/0 Pa!" a$' 7&"&# %7 "3 1a8$ "(9 S&$+ S%la# "L($! a! a " !"C ' 7%# !%la# '6$a1% 1%' l! 1K+20 , 1K+50 Fa$ian Menezes ('RAAM.U/,0 I !&C" #a3 #"D S&$+ *&a"%#(al a$' /%la# #a'(( 7#%1 SST a$' ALMA 1K+50 , 18+00 Amanda C+ R%$io (IAG.US/0 Ba6 !(a$ ($7 #
    [Show full text]
  • Meeting Program
    A A S MEETING PROGRAM 211TH MEETING OF THE AMERICAN ASTRONOMICAL SOCIETY WITH THE HIGH ENERGY ASTROPHYSICS DIVISION (HEAD) AND THE HISTORICAL ASTRONOMY DIVISION (HAD) 7-11 JANUARY 2008 AUSTIN, TX All scientific session will be held at the: Austin Convention Center COUNCIL .......................... 2 500 East Cesar Chavez St. Austin, TX 78701 EXHIBITS ........................... 4 FURTHER IN GRATITUDE INFORMATION ............... 6 AAS Paper Sorters SCHEDULE ....................... 7 Rachel Akeson, David Bartlett, Elizabeth Barton, SUNDAY ........................17 Joan Centrella, Jun Cui, Susana Deustua, Tapasi Ghosh, Jennifer Grier, Joe Hahn, Hugh Harris, MONDAY .......................21 Chryssa Kouveliotou, John Martin, Kevin Marvel, Kristen Menou, Brian Patten, Robert Quimby, Chris Springob, Joe Tenn, Dirk Terrell, Dave TUESDAY .......................25 Thompson, Liese van Zee, and Amy Winebarger WEDNESDAY ................77 We would like to thank the THURSDAY ................. 143 following sponsors: FRIDAY ......................... 203 Elsevier Northrop Grumman SATURDAY .................. 241 Lockheed Martin The TABASGO Foundation AUTHOR INDEX ........ 242 AAS COUNCIL J. Craig Wheeler Univ. of Texas President (6/2006-6/2008) John P. Huchra Harvard-Smithsonian, President-Elect CfA (6/2007-6/2008) Paul Vanden Bout NRAO Vice-President (6/2005-6/2008) Robert W. O’Connell Univ. of Virginia Vice-President (6/2006-6/2009) Lee W. Hartman Univ. of Michigan Vice-President (6/2007-6/2010) John Graham CIW Secretary (6/2004-6/2010) OFFICERS Hervey (Peter) STScI Treasurer Stockman (6/2005-6/2008) Timothy F. Slater Univ. of Arizona Education Officer (6/2006-6/2009) Mike A’Hearn Univ. of Maryland Pub. Board Chair (6/2005-6/2008) Kevin Marvel AAS Executive Officer (6/2006-Present) Gary J. Ferland Univ. of Kentucky (6/2007-6/2008) Suzanne Hawley Univ.
    [Show full text]
  • Dwarf Galaxies
    Europeon South.rn Ob.ervotory• ESO ML.2B~/~1 ~~t.· MAIN LIBRAKY ESO Libraries ,::;,q'-:;' ..-",("• .:: 114 ML l •I ~ -." "." I_I The First ESO/ESA Workshop on the Need for Coordinated Space and Ground-based Observations - DWARF GALAXIES Geneva, 12-13 May 1980 Report Edited by M. Tarenghi and K. Kjar - iii - INTRODUCTION The Space Telescope as a joint undertaking between NASA and ESA will provide the European community of astronomers with the opportunity to be active partners in a venture that, properly planned and performed, will mean a great leap forward in the science of astronomy and cosmology ­ in our understanding of the universe. The European share, however,.of at least 15% of the observing time with this instrumentation, if spread over all the European astrono­ mers, does not give a large amount of observing time to each individual scientist. Also, only well-planned co­ ordinated ground-based observations can guarantee success in interpreting the data and, indeed, in obtaining observ­ ing time on the Space Telescope. For these reasons, care­ ful planning and cooperation between different European groups in preparing Space Telescope observing proposals would be very essential. For these reasons, ESO and ESA have initiated a series of workshops on "The Need for Coordinated Space and Ground­ based Observations", each of which will be centred on a specific subject. The present workshop is the first in this series and the subject we have chosen is "Dwarf Galaxies". It was our belief that the dwarf galaxies would be objects eminently suited for exploration with the Space Telescope, and I think this is amply confirmed in these proceedings of the workshop.
    [Show full text]
  • The Infrared Surface Brightness Fluctuation Distances to the Hydra
    The Infrared Surface Brightness Fluctuation Distances to the Hydra and Coma Clusters 1 Joseph B. Jensen John L. Tonry and Gerard A. Luppino Institute for Astronomy, UniversityofHawaii 2680 Woodlawn Drive, Honolulu, HI 96822 e-mail: [email protected], [email protected], [email protected] ABSTRACT We present IR surface brightness uctuation (SBF) distance measurements to NGC 4889 in the Coma cluster and to NGC 3309 and NGC 3311 in the Hydra cluster. We explicitly corrected for the contributions to the uctuations from globular clusters, background galaxies, and residual background variance. We measured a distance of 85 10 Mp c to NGC 4889 and a distance of 46 5 Mp c to the Hydra cluster. 1 1 Adopting recession velo cities of 7186 428 km s for Coma and 4054 296 km s 1 1 for Hydra gives a mean Hubble constantofH =87 11km s Mp c . Corrections 0 for residual variances were a signi cant fraction of the SBF signal measured, and, if underestimated, would bias our measurementtowards smaller distances and larger values of H . Both NICMOS on the Hubble Space Telescop e and large-ap erture 0 ground-based telescop es with new IR detectors will make accurate SBF distance measurements p ossible to 100 Mp c and b eyond. Subject headings: distance scale | galaxies: clusters: individual (Hydra, Coma) | galaxies: individual (NGC 3309, NGC 3311, NGC 4889) | galaxies: distances and redshifts 1. Intro duction Measuring accurate and reliable distances is a critical part of the quest to measure the Hubble constant H .Until recently, di erenttechniques for estimating extragalactic distances 0 1 Currently with the Gemini 8-m Telescop es Pro ject, 180 Kino ole St.
    [Show full text]
  • 407 a Abell Galaxy Cluster S 373 (AGC S 373) , 351–353 Achromat
    Index A Barnard 72 , 210–211 Abell Galaxy Cluster S 373 (AGC S 373) , Barnard, E.E. , 5, 389 351–353 Barnard’s loop , 5–8 Achromat , 365 Barred-ring spiral galaxy , 235 Adaptive optics (AO) , 377, 378 Barred spiral galaxy , 146, 263, 295, 345, 354 AGC S 373. See Abell Galaxy Cluster Bean Nebulae , 303–305 S 373 (AGC S 373) Bernes 145 , 132, 138, 139 Alnitak , 11 Bernes 157 , 224–226 Alpha Centauri , 129, 151 Beta Centauri , 134, 156 Angular diameter , 364 Beta Chamaeleontis , 269, 275 Antares , 129, 169, 195, 230 Beta Crucis , 137 Anteater Nebula , 184, 222–226 Beta Orionis , 18 Antennae galaxies , 114–115 Bias frames , 393, 398 Antlia , 104, 108, 116 Binning , 391, 392, 398, 404 Apochromat , 365 Black Arrow Cluster , 73, 93, 94 Apus , 240, 248 Blue Straggler Cluster , 169, 170 Aquarius , 339, 342 Bok, B. , 151 Ara , 163, 169, 181, 230 Bok Globules , 98, 216, 269 Arcminutes (arcmins) , 288, 383, 384 Box Nebula , 132, 147, 149 Arcseconds (arcsecs) , 364, 370, 371, 397 Bug Nebula , 184, 190, 192 Arditti, D. , 382 Butterfl y Cluster , 184, 204–205 Arp 245 , 105–106 Bypass (VSNR) , 34, 38, 42–44 AstroArt , 396, 406 Autoguider , 370, 371, 376, 377, 388, 389, 396 Autoguiding , 370, 376–378, 380, 388, 389 C Caldwell Catalogue , 241 Calibration frames , 392–394, 396, B 398–399 B 257 , 198 Camera cool down , 386–387 Barnard 33 , 11–14 Campbell, C.T. , 151 Barnard 47 , 195–197 Canes Venatici , 357 Barnard 51 , 195–197 Canis Major , 4, 17, 21 S. Chadwick and I. Cooper, Imaging the Southern Sky: An Amateur Astronomer’s Guide, 407 Patrick Moore’s Practical
    [Show full text]
  • The Dynamically Hot Stellar Halo Around NGC 3311: a Small Cluster-Dominated Central Galaxy,
    A&A 520, L9 (2010) Astronomy DOI: 10.1051/0004-6361/201015485 & c ESO 2010 Astrophysics Letter to the Editor The dynamically hot stellar halo around NGC 3311: a small cluster-dominated central galaxy, G. Ventimiglia1,2,O.Gerhard1, M. Arnaboldi2,3, and L. Coccato1 1 Max-Plank-Institut für Extraterrestrische Physik, Giessenbachstraβe 1, 85741 Garching bei München, Germany e-mail: [email protected] 2 European Southern Observatory, Karl-Schwarzschild-Straβe 2, 85748 Garching bei München, Germany 3 INAF, Osservatorio Astronomico di Pino Torinese, 10025 Pino Torinese, Italy Received 27 July 2010 / Accepted 10 September 2010 ABSTRACT Context. An important open question is the relation between intracluster light and the halos of central galaxies in galaxy clusters. Aims. Here we report results from an on going project with the aim to characterize the dynamical state in the core of the Hydra I (Abell 1060) cluster around NGC 3311. Methods. We analyze deep long-slit absorption line spectra reaching out to ∼25 kpc in the halo of NGC 3311. −1 −1 Results. We find a very steep increase in the velocity dispersion profile from a central σ0 = 150 km s to σout 450 km s at R 12 kpc. Farther out, to ∼25 kpc, σ appears to be constant at this value, which is ∼60% of the velocity dispersion of the Hydra I galaxies. With its dynamically hot halo kinematics, NGC 3311 is unlike other normal early-type galaxies. Conclusions. These results and the large amount of dark matter inferred from X-rays around NGC 3311 suggest that the stellar halo of this galaxy is dominated by the central intracluster stars of the cluster, and that the transition from predominantly galaxy-bound stars to cluster stars occurs in the radial range 4 to 12 kpc from the center of NGC 3311.
    [Show full text]
  • Aaron J. Romanowsky Curriculum Vitae (Rev. 1 Septembert 2021) Contact Information: Department of Physics & Astronomy San
    Aaron J. Romanowsky Curriculum Vitae (Rev. 1 Septembert 2021) Contact information: Department of Physics & Astronomy +1-408-924-5225 (office) San Jose´ State University +1-409-924-2917 (FAX) One Washington Square [email protected] San Jose, CA 95192 U.S.A. http://www.sjsu.edu/people/aaron.romanowsky/ University of California Observatories +1-831-459-3840 (office) 1156 High Street +1-831-426-3115 (FAX) Santa Cruz, CA 95064 [email protected] U.S.A. http://www.ucolick.org/%7Eromanow/ Main research interests: galaxy formation and dynamics – dark matter – star clusters Education: Ph.D. Astronomy, Harvard University Nov. 1999 supervisor: Christopher Kochanek, “The Structure and Dynamics of Galaxies” M.A. Astronomy, Harvard University June 1996 B.S. Physics with High Honors, June 1994 College of Creative Studies, University of California, Santa Barbara Employment: Professor, Department of Physics & Astronomy, Aug. 2020 – present San Jose´ State University Associate Professor, Department of Physics & Astronomy, Aug. 2016 – Aug. 2020 San Jose´ State University Assistant Professor, Department of Physics & Astronomy, Aug. 2012 – Aug. 2016 San Jose´ State University Research Associate, University of California Observatories, Santa Cruz Oct. 2012 – present Associate Specialist, University of California Observatories, Santa Cruz July 2007 – Sep. 2012 Researcher in Astronomy, Department of Physics, Oct. 2004 – June 2007 University of Concepcion´ Visiting Adjunct Professor, Faculty of Astronomical and May 2005 Geophysical Sciences, National University of La Plata Postdoctoral Research Fellow, School of Physics and Astronomy, June 2002 – Oct. 2004 University of Nottingham Postdoctoral Fellow, Kapteyn Astronomical Institute, Oct. 1999 – May 2002 Rijksuniversiteit Groningen Research Fellow, Harvard-Smithsonian Center for Astrophysics June 1994 – Oct.
    [Show full text]
  • Soft X-Ray Properties of a Spectroscopically Selected Sample of Interacting and Isolated Seyfert Galaxies?
    A&A 368, 797–816 (2001) Astronomy DOI: 10.1051/0004-6361:20010055 & c ESO 2001 Astrophysics Soft X-ray properties of a spectroscopically selected sample of interacting and isolated Seyfert galaxies? F. Pfefferkorn1, Th. Boller1, and P. Rafanelli2 1 Max-Planck-Institut f¨ur extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany 2 Department of Astronomy, University of Padova, Vicolo Osservatorio 5, 35122 Padova, Italy Received 12 October 2000 / Accepted 4 January 2001 Abstract. We present a catalogue of ROSAT detected sources in the sample of spectroscopically selected Seyfert 1 and Seyfert 2 galaxies of Rafanelli et al. (1995). The catalogue contains 102 Seyfert 1 and 36 Seyfert 2 galaxies. The identification is based on X-ray contour maps overlaid on optical images taken from the Digitized Sky Survey. We have derived the basic spectral and timing properties of the X-ray detected Seyfert galaxies. For Seyfert 1 galaxies a strong correlation between photon index and X-ray luminosity is detected. We confirm the presence of generally steeper X-ray continua in narrow-line Seyfert 1 galaxies (NLS1s) compared to broad-line Seyfert 1 galaxies. Seyfert 2 galaxies show photon indices similar to those of NLS1s. Whereas a tendency for an increasing X-ray luminosity with increasing interaction strength is found for Seyfert 1 galaxies, such a correlation is not found for Seyfert 2 galaxies. For Seyfert 1 galaxies we found also a strong correlation for increasing far-infrared luminosity with increasing interaction strength. Both NLS1s and Seyfert 2 galaxies show the highest values of far-infrared luminosity compared to Seyfert 1 galaxies, suggesting that NLS1s and Seyfert 2 galaxies host strong (circumnuclear) star formation.
    [Show full text]