J/ApJ/773/L27 Globular clusters in ACSVCS early-type galaxies (Park+, 2013)
Dual halos and formation of early-type galaxies.
Park H.S., Lee M.G.
<Astrophys. J., 773, L27 (2013)>
=2013ApJ...773L..27P 2013ApJ...773L..27P
ADC_Keywords: Galaxies, optical ; Clusters, globular ; Morphology
Keywords: galaxies: elliptical and lenticular, cD; galaxies: formation;
galaxies: halos; galaxies: star clusters: general; galaxies: structure
Abstract:
We present a determination of the two-dimensional shape parameters of
the blue and red globular cluster systems (GCSs) in a large number of
elliptical galaxies and lenticular galaxies (early-type galaxies,
called ETGs). We use a homogeneous data set of the globular clusters
in 23 ETGs obtained from the HST/ACS Virgo Cluster Survey. The
position angles of both blue and red GCSs show a correlation with
those of the stellar light distribution, showing that the major axes
of the GCSs are well aligned with those of their host galaxies.
However, the shapes of the red GCSs show a tight correlation with the
stellar light distribution as well as with the rotation property of
their host galaxies, while the shapes of the blue GCSs do much less.
These provide clear geometric evidence that the origins of the blue
and red globular clusters are distinct and that ETGs may have dual
halos: a blue (metal-poor) halo and a red (metal-rich) halo. These two
halos show significant differences in metallicity, structure, and
kinematics, indicating that they are formed in two distinguishable
ways. The red halos might have formed via dissipational processes with
rotation, while the blue halos are through accretion.
Description:
We used data for the position and photometry of the globular clusters
(GCs) in bright early-type galaxies (ETGs; elliptical galaxies and
lenticular galaxies) of the Virgo cluster given in the ACSVCS (ACS
Virgo Cluster survey; Jordan et al. 2009, J/ApJS/180/54). ACSVCS is
a homogeneous gz imaging survey of a sample of 100 ETGs in Virgo with
the HST (Cote et al. 2004, J/ApJS/153/223; Ferrarese et al. 2006,
J/ApJS/164/334).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 55 69 Shape parameters for the globular cluster
systems (GCSs) in 23 bright early-type galaxies
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
J/MNRAS/428/389 : SLUGGS GCs in early-type galaxies (Pota+, 2013)
J/ApJ/759/116 : Chemical analysis of NGC 4636 GCs (Park+, 2012)
J/A+A/543/A131 : NGC1316 globular cluster candidates phot. (Richtler+, 2012)
J/ApJ/746/88 : HST observations of GCs in NGC 1399 (Blakeslee+, 2012)
J/ApJS/197/33 : The M87 globular cluster system (Strader+, 2011)
J/ApJ/743/149 : Color-metallicity relations. II. M87 GCs (Yoon+, 2011)
J/MNRAS/416/1680 : ATLAS3D project. VII. (Cappellari+, 2011)
J/ApJ/708/1335 : Spectroscopy of globulars in NGC 5128 (Woodley+, 2010)
J/ApJS/182/216 : Surface photometry of Virgo ellipticals (Kormendy+, 2009)
J/ApJS/180/54 : GC candidates in ACS Virgo survey. (Jordan+, 2009)
J/ApJ/682/135 : CCD photometry of M60 (Lee+, 2008)
J/ApJ/681/197 : ACS Virgo Cluster Survey. XV (Peng+, 2008)
J/ApJS/164/334 : ACS Virgo Cluster Survey. VI (Ferrarese+, 2006)
J/A+A/433/43 : C-T1 phot. of NGC 4636 GC system (Dirsch+, 2005)
J/ApJS/153/223 : ACS Virgo Cluster Survey (ACSVCS). I. (Cote+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- n_VCC Subset flag on VCC (1)
6- 9 I4 --- VCC [685/2095] Virgo Cluster Catalog identifier
11- 14 I4 --- N [24/1468] Number of globular clusters in set
16- 19 F4.1 arcsec MajAxis [28.9/59] Major axis length of GC system
21- 23 F3.1 arcsec e_MajAxis [0.7/6] Error in MajAxis
25- 28 F4.1 arcsec MinAxis [11/53] Minor axis length of GC system
30- 32 F3.1 arcsec e_MinAxis [0.7/6] Error in MinAxis
34- 38 F5.1 deg PA [13/180] Position angle of GC system
40- 43 F4.1 deg e_PA [4/54] Error in PA
45- 49 F5.3 --- Ell [0.01/0.7] Ellipticity of GC system
51- 55 F5.3 --- e_Ell [0.01/0.2] Error in Ell
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Note (1): Subset flag as follows:
All = Entire globular cluster sample;
Blue = Blue globular cluster sample ((g-z)0<1.1);
Red = Red globular cluster sample ((g-z)0>1.1).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 24-Feb-2015