J/AJ/142/199 Sizes and luminosities of stellar systems (Brodie+, 2011)
The relationships among compact stellar systems: a fresh view of ultracompact
dwarfs.
Brodie J.P., Romanowsky A.J., Strader J., Forbes D.A.
<Astron. J., 142, 199 (2011)>
=2011AJ....142..199B 2011AJ....142..199B
ADC_Keywords: Galaxies, nearby ; Associations, stellar ; Morphology ;
Photometry
Keywords: galaxies: dwarf - galaxies: individual (M87) - galaxies: nuclei -
galaxies: star clusters: general - galaxies: structure -
globular clusters: general
Abstract:
We use a combined imaging and spectroscopic survey of the nearby
central cluster galaxy, M87, to assemble a sample of 34 confirmed
UltraCompact Dwarfs (UCDs) with half-light radii of ≥10pc measured
from Hubble Space Telescope (HST) images. This doubles the existing
sample in M87, making it the largest such sample for any galaxy, while
extending the detection of UCDs to unprecedentedly low luminosities
(MV=-9). With this expanded sample, we find no correlation between
size and luminosity, in contrast to previous suggestions, and no
general correlation between size and galactocentric distance. We
explore the relationships between UCDs, less luminous extended
clusters (including faint fuzzies), Globular Clusters (GCs), as well
as early-type galaxies and their nuclei, assembling an extensive new
catalog of sizes and luminosities for stellar systems. Most of the M87
UCDs follow a tight color-magnitude relation, offset from the
metal-poor GCs. This, along with kinematical differences, demonstrates
that most UCDs are a distinct population from normal GCs, and not
simply a continuation to larger sizes and higher luminosities. The UCD
color-magnitude trend couples closely with that for Virgo dwarf
elliptical nuclei. We conclude that the M87 UCDs are predominantly
stripped nuclei. The brightest and reddest UCDs may be the remnant
nuclei of more massive galaxies while a subset of the faintest UCDs
may be tidally limited and related to more compact star clusters. In
the broader context of galaxy assembly, blue UCDs may trace halo
build-up by accretion of low-mass satellites, while red UCDs may be
markers of metal-rich bulge formation in larger galaxies.
Description:
We assemble from the literature a compilation of the sizes and
luminosities of hot stellar systems, from the largest galaxies to the
smallest GCs. We restrict the sample to objects with distances
confirmed either by spectroscopy, surface brightness fluctuations, or
resolved stellar populations. In order to not complicate the analysis
with large stellar mass-to-light ratio variations, we also include
only old objects (ages≥5Gyr) where possible, e.g., excluding some
young, ECs that are known in the Large Magellanic Cloud and beyond.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 68 970 Catalog of sizes and luminosities for
nearby stellar systems
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See also:
J/ApJ/604/521 : Luminosities and masses of galaxies out to z∼3 (Trujillo+ 2004)
J/AJ/133/2764 : M31 globular clusters structural parameters (Barmby+, 2007)
J/A+A/472/111 : Centaurus Compact Object Survey (Mieske+, 2007)
J/AJ/137/4956 : Globular clusters around NGC 1407 (Romanowsky+, 2009)
J/MNRAS/414/3699 : Study of hot stellar systems and galaxies (Misgeld+, 2011)
J/MNRAS/415/3393 : Stars and globulars in NGC4494 (Foster+, 2011)
J/ApJS/197/33 : The M87 globular cluster system (Strader+, 2011)
J/ApJ/737/86 : UCD galaxies in the Coma cluster (Chiboucas+, 2011)
J/A+A/531/A4 : Ultra compact dwarfs and globulars in Hya I (Misgeld+, 2011)
J/AJ/142/88 : Segue 3 photometric and kinematic data (Fadely+, 2011)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 27 A27 --- ID Stellar system identification (1)
29- 45 A17 --- Host Host/Environment
47- 52 F6.2 mag VMag [-24.61/-0.06] Absolute V band magnitude (2)
54- 58 F5.3 [pc] logrh [0/4.537] Log of half-light radius (2)
60- 68 A9 --- Ref Reference (3)
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Note (1): The data table is arranged in ascending order by luminosity.
Note (2): In many cases the precision of the size or magnitude measurements is
higher than the actual measurement uncertainties, but the additional
significant figures are kept in order to avoid discreteness effects
in the plots. All magnitudes are extinction corrected.
Note (3): References as follows:
B+07 = Barmby et al. (2007, Cat. J/AJ/133/2764);
B+11 = Brasseur et al. (2011ApJ...743..179B 2011ApJ...743..179B);
BL02 = Brodie & Larsen (2002AJ....124.1410B 2002AJ....124.1410B);
C+09 = Chilingarian et al. (2009Sci...326.1379C 2009Sci...326.1379C);
C+11a = Cockcroft et al. (2011ApJ...730..112C 2011ApJ...730..112C);
C+11b = Chiboucas et al. (2011, Cat. J/ApJ/737/86);
D+09 = Da Costa et al. (2009AJ....137.4361D 2009AJ....137.4361D);
F+11a = Forbes et al. (2011MNRAS.413.2665F 2011MNRAS.413.2665F);
F+11b = Foster et al. (2011, Cat. J/MNRAS/415/3393);
F+11c = Fadely et al. (2011, Cat. J/AJ/142/88);
G+03 = Geha et al. (2003AJ....126.1794G 2003AJ....126.1794G);
H+05 = Hasegan et al. (2005ApJ...627..203H 2005ApJ...627..203H);
H07 = Hasegan (2007, PhD thesis);
H+09 = Hau et al. (2009MNRAS.394L..97H 2009MNRAS.394L..97H);
H10 = Harris(2010, 1012.3224);
H+11a = Huxor et al. (2011MNRAS.414..770H 2011MNRAS.414..770H);
H+11b = Hwang et al. (2011ApJ...738...58H 2011ApJ...738...58H);
LB00 = Larsen & Brodie (2000AJ....120.2938L 2000AJ....120.2938L);
M+07 = Mieske et al. (2007, Cat. J/A+A/472/111);
M+08 = Martin et al. (2008ApJ...684.1075M 2008ApJ...684.1075M);
M+10 = Mouhcine et al. (2010MNRAS.404.1157M 2010MNRAS.404.1157M);
M+11 = Misgeld et al. (2011, Cat. J/A+A/531/A4);
MH04 = Martini & Ho (2004ApJ...610..233M 2004ApJ...610..233M);
MH11 = Misgeld & Hilker (2011, Cat. J/MNRAS/414/3699);
NK11 = Norris & Kannappan (2011MNRAS.414..739N 2011MNRAS.414..739N);
R+05 = Richtler et al. (2005A&A...439..533R 2005A&A...439..533R);
R+07 = Rejkuba et al. (2007A&A...469..147R 2007A&A...469..147R);
R+09 = Romanowsky et al. (2009, Cat. J/AJ/137/4956);
S+08 = Smith Castelli et al. (2008MNRAS.391..685S 2008MNRAS.391..685S);
S+11 = Strader et al. (2011, Cat. J/ApJS/197/33);
VM04 = van den Bergh & Mackey (2004MNRAS.354..713V 2004MNRAS.354..713V).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 25-Mar-2013