J/ApJ/835/212 Wide-field spectrosc. survey of GCs in Virgo cluster (Ko+, 2017)
To the edge of M87 and beyond: spectroscopy of intracluster globular clusters
and ultracompact dwarfs in the Virgo cluster.
Ko Y., Hwang H.S., Lee M.G., Park H.S., Lim S., Sohn J., Jang I.S.,
Hwang N., Park B.-G.
<Astrophys. J., 835, 212-212 (2017)>
=2017ApJ...835..212K 2017ApJ...835..212K (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Photometry, ugriz ; Radial velocities ;
Clusters, globular
Keywords: galaxies: clusters: individual: Virgo;
galaxies: elliptical and lenticular, cD;
galaxies: individual: M87; globular clusters: general;
galaxies: kinematics and dynamics; galaxies: star clusters: general
Abstract:
We present the results of a wide-field spectroscopic survey of
globular clusters (GCs) in the Virgo cluster. We obtain spectra for
201 GCs and 55 ultracompact dwarfs (UCDs) using Hectospec on the
Multiple-Mirror Telescope and derive their radial velocities. We
identify 46 genuine intracluster GCs (IGCs), not associated with any
Virgo galaxies, using the 3D GMM test on the spatial and radial
velocity distribution. They are located at a projected distance
200kpc≲R≲500kpc from the center of M87. The radial velocity
distribution of these IGCs shows two peaks, one at vr=1023km/s,
associated with the Virgo main body, and another at vr=36km/s,
associated with the infalling structure. The velocity dispersion of
the IGCs in the Virgo main body is σGC∼314km/s, which is
smoothly connected to the velocity dispersion profile of M87 GCs but
is much lower than that of dwarf galaxies in the same survey field,
σdwarf∼608km/s. The UCDs are more centrally concentrated on
massive galaxies-M87, M86, and M84. The radial velocity dispersion of
the UCD system is much smaller than that of dwarf galaxies. Our
results confirm the large-scale distribution of Virgo IGCs indicated
by previous photometric surveys. The color distribution of the
confirmed IGCs shows a bimodality similar to that of M87 GCs. This
indicates that most IGCs are stripped off dwarf galaxies and some off
massive galaxies in the Virgo.
Description:
We selected globular cluster (GC) candidates using the Next Generation
Virgo Cluster Survey (NGVS; Ferrarese+ 2012ApJS..200....4F 2012ApJS..200....4F) archival
images covering the central region of the Virgo cluster. The NGVS is a
wide-field imaging survey of the Virgo cluster using MegaCam with a
field of view of 1°x1° attached at the Canada-French-Hawaii
Telescope.
We carried out spectroscopic observation of GC candidates in the Virgo
using the Hectospec mounted on the 6.5m Multiple-Mirror Telescope in
queue mode under program ID 2014A-UAO-G18 (PI: Myung Gyoon Lee)
between 2014 February and March (wavelength range: 3650Å to 9200Å).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 76 635 Spectroscopic and photometric properties of
foreground stars and background galaxies
table3.dat 119 633 Spectroscopic and photometric properties of
the combined globular cluster (GC) sample
table4.dat 103 138 Spectroscopic and photometric properties of
the combined ultracompact dwarf (UCD) sample
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See also:
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/AJ/90/1681 : The Virgo Cluster Catalog (VCC) (Binggeli+, 1985)
J/A+AS/139/393 : Young Massive Star Clusters. II. (Larsen, 1999)
J/A+A/383/823 : Radial velocities of UCOs in Fornax (Mieske+, 2002)
J/A+A/464/L21 : Velocities of globular clusters in Fornax (Bergond+, 2007)
J/ApJ/655/144 : ACS Virgo Cluster Survey. XIII. (Mei+, 2007)
J/A+A/477/L9 : Globular clusters around NGC 1399 (Schuberth+, 2008)
J/MNRAS/396/1075 : GC in nearby dwarf galaxies. II (Georgiev+, 2009)
J/ApJS/180/54 : GC candidates in ACS Virgo survey. (Jordan+, 2009)
J/ApJS/182/216 : Surface photometry of Virgo ellipticals (Kormendy+, 2009)
J/MNRAS/402/803 : M31 globular cluster system (Peacock+, 2010)
J/A+A/513/A52 : Velocities of NGC 1399 globular clusters (Schuberth+, 2010)
J/AJ/142/199 : Sizes and luminosities of stellar systems (Brodie+, 2011)
J/A+A/531/A4 : Ultra compact dwarfs and globulars in Hya I (Misgeld+, 2011)
J/ApJS/197/33 : The M87 globular cluster system (Strader+, 2011)
J/ApJ/748/29 : Spectroscopy of M87 globular clusters (Romanowsky+, 2012)
J/ApJS/215/22 : The Extended Virgo Cluster Catalog (EVCC) (Kim+, 2014)
J/ApJ/802/30 : NGVS VI. Ultra-compact dwarfs in M87 (Zhang+, 2015)
J/MNRAS/455/820 : M87 globular cluster candidates catalog (Oldham+, 2016)
J/ApJS/227/12 : NGVS XXV. Virgo globular clusters photometry (Powalka+, 2016)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- S/G "STAR" or "GAL"
5- 7 I03 --- Seq Running sequence number within S/G class
9- 18 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
20- 28 F9.6 deg DEdeg Declination in decimal degrees (J2000)
30- 35 F6.3 mag imag [17.1/21] CFHT/MegaCam i band AB magnitude
37- 41 F5.3 mag e_imag [0/0.007] Error in imag
43- 47 F5.3 mag g-r [0.3/1] The (g-r) color index
49- 53 F5.3 mag e_g-r Error in g-r
55- 59 F5.3 mag g-i [0.6/1.7] The (g-i) color index
61- 65 F5.3 mag e_g-i Error in g-i
67- 72 I6 km/s HRV [-295/240245] Heliocentric radial velocity
74- 76 I3 km/s e_HRV [4/431] Error in HRV
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- ID Identification (1)
8- 17 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
19- 27 F9.6 deg DEdeg Declination in decimal degrees (J2000)
29- 34 F6.3 mag imag [17.8/23.5] i band AB magnitude
36- 40 F5.3 mag e_imag [0.001/0.02]? Error in imag
42- 46 F5.3 mag g-r [0.3/0.9]? The (g-r) color index
48- 52 F5.3 mag e_g-r ? Error in g-r
54- 58 F5.3 mag g-i [0.6/1.3]? The (g-i) color index
60- 64 F5.3 mag e_g-i ? Error in g-i
66- 68 A3 --- r_phot Source of photometry (2)
70- 73 I4 km/s HRV [-728/2777] Heliocentric radial velocity
75- 77 I3 km/s e_HRV [5/114] Error in HRV
79- 81 A3 --- r_HRV Source of HRV (2)
83- 85 F3.1 pc rh [1.3/9.2]? Half-light radius
87- 89 F3.1 pc E_rh [0/1.5]? Upper error in rh
91- 93 F3.1 pc e_rh [0/1.1]? Lower error in rh
95- 97 A3 --- r_rh ? Source of rh (2)
99-111 A13 --- Gal1 Host galaxy determined by Mclust method (3)
113-119 A7 --- Gal2 Host galaxy determined by Rv cut method
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Note (1): GCNNN for sources from this study or HNNNNN/TNNNNN for sources from
Strader et al. (2011, J/ApJS/197/33; <[SRB2011] {HT}NNNNN> in Simbad)
or SNNNN for sources from Hanes+, 2001, J/ApJ/559/812;
<[SFH81] NNNN> in Simbad.
Note (2): Reference as follows:
K16 = this study.
S11 = Strader et al. (2011, J/ApJS/197/33).
J09 = Jordan et al. (2009, J/ApJS/180/54).
The magnitudes of this study and S11 are CFHT/MegaCam AB
and dereddened SDSS AB magnitudes, respectively.
Note (3): The Mclust subgroup that a given UCD belongs to is in parentheses.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- ID Identification (1)
11- 20 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
22- 30 F9.6 deg DEdeg Declination in decimal degrees (J2000)
32- 37 F6.3 mag imag [17.5/22.3] i band AB magnitude
39- 43 F5.3 mag e_imag [0.001/0.02]? Error in imag
45- 49 F5.3 mag g-r [0.4/0.8]? The (g-r) color index
51- 55 F5.3 mag e_g-r ? Error in g-r
57- 61 F5.3 mag g-i [0.6/1.2]? The (g-i) color index
63- 67 F5.3 mag e_g-i ? Error in g-i
69- 71 A3 --- r_phot Source of photometry (2)
73- 76 I4 km/s HRV [-416/2419] Heliocentric radial velocity
78- 80 I3 km/s e_HRV [2/146] Error in HRV
82- 84 A3 --- r_HRV Source of HRV (2)
86- 89 F4.1 pc rh [0.6/40.2]? Half-light radius
91- 93 F3.1 pc E_rh [0/8.4]? Upper error in rh
95- 97 F3.1 pc e_rh [0/8.4]? Lower error in rh
99-101 A3 --- r_rh ? Source of rh (2)
103-103 A1 --- Mcl [A-C] Mclust subgroup that a given UCD belongs to
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Note (1): UCDNN for sources from this study or M87UCD-NN for sources from
Zhang et al. (2015, J/ApJ/802/30; <[ZPC2015] M87UCD NN> in Simbad) or
SNNNN for sources from Hanes+, 2001, J/ApJ/559/812;
<[SFH81] NNNN> in Simbad or HNNNNN/TNNNNN for sources from
Strader et al. (2011, J/ApJS/197/33; <[SRB2011] {HT}NNNNN> in Simbad).
Note (2): Reference as follows:
K16 = this study.
Z15 = Zhang et al. (2015, J/ApJ/802/30).
J09 = Jordan et al. (2009, J/ApJS/180/54).
The magnitudes of this study and Z15 are CFHT/MegaCam AB and
dereddened SDSS AB magnitudes, respectively.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 31-Aug-2017