J/ApJS/197/33 The M87 globular cluster system (Strader+, 2011)
Wide-field precision kinematics of the M87 globular cluster system.
Strader J., Romanowsky A.J., Brodie J.P., Spitler L.R., Beasley M.A.,
Arnold J.A., Tamura N., Sharples R.M., Arimoto N.
<Astrophys. J. Suppl. Ser., 197, 33 (2011)>
=2011ApJS..197...33S 2011ApJS..197...33S
ADC_Keywords: Clusters, globular ; Photometry ; Radial velocities ;
Galaxies, nearby
Keywords: dark matter - galaxies: elliptical and lenticular, cD -
galaxies: individual (M87) - galaxies: kinematics and dynamics -
galaxies: star clusters: general - globular clusters: general
Abstract:
We present the most extensive combined photometric and spectroscopic
study to date of the enormous globular cluster (GC) system around M87,
the central giant elliptical galaxy in the nearby Virgo Cluster. Using
observations from DEIMOS and the Low Resolution Imaging Spectrometer
at Keck, and Hectospec on the Multiple Mirror Telescope, we derive
new, precise radial velocities for 451 GCs around M87, with projected
radii from ∼5 to 185kpc. We combine these measurements with literature
data for a total sample of 737 objects, which we use for a
re-examination of the kinematics of the GC system of M87. The
velocities are analyzed in the context of archival wide-field
photometry and a novel Hubble Space Telescope catalog of half-light
radii, which includes sizes for 344 spectroscopically confirmed
clusters. We use this unique catalog to identify 18 new candidate
ultracompact dwarfs and to help clarify the relationship between these
objects and true GCs.
Description:
We selected GC candidates from the Subaru/Suprime-Cam imaging study of
Tamura et al. (2006MNRAS.373..588T 2006MNRAS.373..588T).
Spectroscopic data were obtained from Keck/DEIMOS in 2007 Mar 20 and
21 and in 2010 Mar 12, from Keck/Low Resolution Spectrometer (LRIS) in
2010 Apr 8-11 and from Multiple Mirror Telescope (MMT)/Hectospec in
2010 Feb 17.
We chose to use for our default GC photometry the new gri CFHT/Megacam
imaging of M87 published in Harris (2009ApJ...703..939H 2009ApJ...703..939H).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 58 254 Data for Keck/DEIMOS spectroscopic candidates
table3.dat 56 29 Data for supplementary Keck/DEIMOS spectroscopy
table4.dat 56 244 Data for MMT/Hectospec spectroscopic candidates
table5.dat 56 209 Data for Keck/LRIS spectroscopic candidates
table6.dat 125 114 Globular cluster/Ultracompact dwarfs (UCDs)
radial velocities with multiple measurements
table7.dat 25 197 New half-light radii
table8.dat 93 189 Spectroscopic data for all foreground stars
table9.dat 111 739 Spectroscopic and photometric data for all M87
globular clusters and ultracompact dwarfs
table10.dat 44 591 Supplementary photometric data for M87 globular
clusters and ultracompact dwarfs
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See also:
J/ApJS/180/54 : Globular cluster candidates in ACS Virgo survey. (Jordan+,
2009)
J/ApJ/703/42 : HST photometry of M87 globular clusters (Peng+, 2009)
J/AJ/131/866 : Hot populations in M87 globular clusters (Sohn+, 2006)
J/ApJ/613/279 : ACS Virgo Cluster Survey. III. M87 (Jordan+, 2004)
J/ApJ/559/812 : Globular cluster system in M87 (Hanes+, 2001)
J/ApJ/513/733 : Globular cluster system in M87 (Kundu+, 1999)
J/AJ/115/1801 : VRI photometry of M87 globular clusters (Harris+ 1998)
J/AJ/106/493 : Globular clusters in M87 (Lee+, 1993)
J/ApJS/73/671 : M87 globular clusters BVI photometry (Couture+, 1990)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- ID Identification (G1)
8- 16 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000) (1)
18- 25 F8.5 deg DEdeg Declination in decimal degrees (J2000) (1)
27- 29 A3 --- Mask [1,4] Mask(s) (2)
31- 35 F5.2 mag Vmag Subaru/Suprime-Cam V band magnitude (1)
37- 40 F4.2 mag B-V Subaru/Suprime-Cam (B-V) color index (1)
42- 45 F4.2 mag V-I Subaru/Suprime-Cam (V-I) color index (1)
47- 50 A4 --- Class Classification (G2)
52- 55 I4 km/s HRV ? Heliocentric radial velocity
57- 58 I2 km/s e_HRV ? Error in HRV
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Note (1): The astrometry and photometry in this table are taken from Tamura
et al. (2006MNRAS.373..588T 2006MNRAS.373..588T); the photometry is corrected for
foreground reddening.
Note (2): We designed four Keck/DEIMOS slit masks, each covering an area of
∼16'x5'. These were arranged with minimal overlap in a 2x2 grid
covering a total area of ∼32'x10', starting ∼8' from the center of M87.
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Byte-by-byte Description of file: table[345].dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- ID Identification (G1)
8- 16 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000)
18- 25 F8.5 deg DEdeg Declination in decimal degrees (J2000)
27 I1 --- Mask [1,4]? Mask (for table 5 only)
29- 33 F5.2 mag imag ? The CFHT/Megacam i band magnitude (1)
35- 38 F4.2 mag g-r ? The CFHT/Megacam (g-r) color index (1)
40- 43 F4.2 mag g-i ? The CFHT/Megacam (g-i) color index (1)
45- 48 A4 --- Class Classification (G2)
50- 53 I4 km/s HRV ? Heliocentric radial velocity
55- 56 I2 km/s e_HRV ? Error in HRV
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Note (1): The photometry is corrected for foreground reddening.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- ID ID Identification (G1)
8 A1 --- f_ID [b] Flag on ID (1)
10- 13 I4 km/s H01 ? Hanes et al. 2001, Cat .J/ApJ/559/812
heliocentric radial velocity
15- 17 I3 km/s e_H01 ? Uncertainty in H01
19- 22 I4 km/s K97 ? Kohen & Ryzhov, 1997ApJ...486..230C 1997ApJ...486..230C,
heliocentric radial velocity
24- 26 I3 km/s e_K97 ? Uncertainty in K97
28- 31 I4 km/s K00 ? Cohen, 2000AJ....119..162C 2000AJ....119..162C, heliocentric
radial velocity
33- 34 I2 km/s e_K00 ? Uncertainty in K00
36- 39 I4 km/s M90 ? Mould et al., 1990AJ.....99.1823M 1990AJ.....99.1823M,
heliocentric radial velocity
41- 43 I3 km/s e_M90 ? Uncertainty in M90
45- 48 I4 km/s M87 ? Mould et al., 1987AJ.....93...53M 1987AJ.....93...53M,
heliocentric radial velocity
50- 52 I3 km/s e_M87 ? Uncertainty in M87
54- 57 I4 km/s HB87 ? Huchra & Brodie, 1987AJ.....93..779H 1987AJ.....93..779H,
heliocentric radial velocity
59- 61 I3 km/s e_HB87 ? Uncertainty in HB87
63- 66 I4 km/s MMT ? This paper, MMT/Hectospec heliocentric radial
velocity
68- 69 I2 km/s e_MMT ? Uncertainty in MMT
71- 74 I4 km/s LRIS ? This paper, Keck/LRIS heliocentric radial
velocity
76- 77 I2 km/s e_LRIS ? Uncertainty in LRIS
79- 82 I4 km/s D1 ? This paper, Keck/DEIMOS run 1 heliocentric
radial velocity
84- 85 I2 km/s e_D1 ? Uncertainty in D1
87- 90 I4 km/s D2 ? This paper, Keck/DEIMOS run 2 heliocentric
radial velocity
92- 93 I2 km/s e_D2 ? Uncertainty in D2
95- 98 I4 km/s H05/H07 ? Hasegan et al., 2005ApJ...627..203H 2005ApJ...627..203H, or
Hasegan 2007PhDT.........4H 2007PhDT.........4H, heliocentric radial
velocity
100-101 I2 km/s e_H05/H07 ? Uncertainty in H05/H07
103-106 I4 km/s J06 ? Jones et al., 2006AJ....131..312J 2006AJ....131..312J,
heliocentric radial velocity
108-110 I3 km/s e_J06 ? Uncertainty in J06
112-115 I4 km/s E07 ? Evstigneeva et al., 2007AJ....133.1722E 2007AJ....133.1722E,
heliocentric radial velocity
117 I1 km/s e_E07 ? Uncertainty in E07
119-122 I4 km/s F08 ? Firth et al., 2008MNRAS.389.1539F 2008MNRAS.389.1539F,
heliocentric radial velocity
124-125 I2 km/s e_F08 ? Uncertainty in F08
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Note (1):
b = "catastrophic" outlier, described in the text.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- ID Star name (G1)
8- 11 F4.1 pc rh ? Half-light radius assuming a distance of 16.5Mpc
12 A1 --- f_rh [d] d: unresolved; the upper limit is rh∼1pc
14- 18 A5 --- Inst Instrument
20- 25 A6 --- Filt Filter (1)
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Note (1): The STIS "50CCD" denotes a clear, unfiltered aperture.
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- ID Star name (G1)
8 A1 --- f_ID [f] Flag on ID (1)
10- 22 A13 --- AID Alternative identification(s) (G1)
24- 32 F9.5 deg RAdeg Right ascension in decimal degrees (J2000)
34- 41 F8.5 deg DEdeg Declination in decimal degrees (J2000)
43 A1 --- f_imag [i] Flag on imag (2)
44- 48 F5.2 mag imag ? The CFHT i-band magnitude
50- 53 F4.2 mag g-r ? The CFHT (g-r) color index
55- 58 F4.2 mag g-i ? The CFHT (g-i) color index
60- 63 I4 km/s HRV Heliocentric radial velocity of the object
65- 67 I3 km/s e_HRV ? HRV uncertainty
69- 91 A23 --- r_HRV Source(s) (3)
93 A1 --- HST [Y/N] Confirmed by high-resolution HST imaging?
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Note (1):
f = This radial velocity is associated with an unidentified member of a
close pair. The values listed are for the source closer to the reported
position; the second object is H51472, coordinates: 187.75358 +12.45462,
i=21.50, g-i=0.87.
Note (2):
i = For objects without CFHT imaging, an extinction-corrected i-band
magnitude has been estimated from the other available photometry.
Note (3): Source of HRV as follows:
H01 = Hanes et al. (2001, Cat. J/ApJ/559/812);
K97 = Cohen & Ryzhov (1997ApJ...486..230C 1997ApJ...486..230C);
M90 = Mould et al. (1990AJ.....99.1823M 1990AJ.....99.1823M);
HB87 = Huchra & Brodie (1987AJ.....93..779H 1987AJ.....93..779H);
MMT = this paper, (MMT/Hectospec);
D1 = this paper, (Keck/DEIMOS run 1);
D2 = this paper, (Keck/DEIMOS run 2);
LRIS = this paper, (Keck/LRIS).
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- ID Identification (G1)
8 A1 --- f_ID [i] Flag on ID (1)
10- 22 A13 --- AID Alternate identification (G1)
24- 32 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000) (2)
34- 41 F8.5 deg DEdeg Declination in decimal degrees (J2000) (2)
43- 47 F5.2 mag imag The CFHT i band magnitude
49 A1 --- f_imag [i] Flag on imag (3)
51- 54 F4.2 mag g-r ? The CFHT (g-r) color index
56- 59 F4.2 mag g-i ? The CFHT (g-i) color index
61- 64 I4 km/s HRV Heliocenric radial velocity
66- 68 I3 km/s e_HRV Error in HRV
70- 88 A19 --- r_HRV Source of HRV (4)
90- 94 F5.1 pc rh ? Half-light radius; assuming D=16.5Mpc
96 A1 --- f_rh [u] Indicates unresolved source for rh
98-100 A3 --- r_rh Source of rh (5)
102-105 A4 --- spop Cluster subpopulation (blue or red) (6)
107-111 A5 --- Class Source classification (7)
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Note (1):
i = As discussed in Section 4.4.4, this GC may be a member of NGC 4478.
Note (2): Right Ascension and Declination were re-calculated using the CFHT
g-band image, and so there may be differences between the listed
coordinates of objects in common between Table 1 and this table.
Several objects outside of the field of view of the CFHT images
retain coordinates from Tamura et al. (2006MNRAS.373..588T 2006MNRAS.373..588T).
Note (3):
i = an object without CFHT imaging thus an extinction-corrected i-band
magnitude was estimated from the other available photometry.
Note (4): Multiple sources are listed chronologically. The sources are as
listed in Table 6, with the addition of P10 (Paudel et al.
2010ApJ...724L..64P 2010ApJ...724L..64P).
Note (5): Reference as follows:
E08 = Evstigneeva et al. (2008AJ....136..461E 2008AJ....136..461E);
H05 = Hasegan et al. (2005ApJ...627..203H 2005ApJ...627..203H);
H07 = Hasegan (2007PhDT.........4H 2007PhDT.........4H);
J09 = Jordan et al. (2009, Cat. J/ApJS/180/54);
L01 = Larsen et al. (2001AJ....121.2974L 2001AJ....121.2974L);
M09 = Madrid et al. (2009ApJ...705..237M 2009ApJ...705..237M);
S11 = This paper.
Note (6): The subpopulation (blue metal-poor or red metal-rich) to which
the cluster belongs, as determined in Section 4.6.
Note (7): Whether the object is classified as a transition object ("trans")
or ultra-compact dwarf ("UCD") on the basis of its half-light radius,
according to the boundaries of 5.25pc and 9.5pc discussed in S 4.4.1.
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- ID Identification (G1)
8- 12 F5.2 mag T1mag ? The Washington T1 band magnitude (1)
14- 17 F4.2 mag C-T1 ? The Washington (C-T1) color index (1)
19- 23 F5.2 mag gmag ? HST/ACS g band magnitude (2)
25- 28 F4.2 mag g-z ? HST/ACS (g-z) color index (2)
30- 34 F5.2 mag Vmag ? The Subaru V band magnitude
36- 39 F4.2 mag B-V ? The Subaru (B-V) color index
41- 44 F4.2 mag V-I ? The Subaru (V-I) color index
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Note (1): From Hanes et al. 2001, Cat. J/ApJ/559/812
Note (2): From Jordan et al., 2009, Cat. J/ApJS/180/54
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Global Notes:
Note (G1): Identifications with "S" are on the extended Strom naming scheme
(see Hanes et al. 2001, Cat. J/ApJ/559/812; <[SFH81] NNNN> for Simbad).
* Those starting with "T" are from Tamura et al. (2006MNRAS.373..588T 2006MNRAS.373..588T).
* The two VUCD IDs are from Jones et al. (2006AJ....131..312J 2006AJ....131..312J;
<[JDJ2006] N> in Simbad).
* Those starting with "H" are from this paper using the imaging first
presented in Harris (2009ApJ...703..939H 2009ApJ...703..939H; <[SRB2011] HNNNNN> in Simbad).
* The "F" ID is from Firth et al. (2008MNRAS.389.1539F 2008MNRAS.389.1539F).
* In table 8, the two objects with Roman numeral IDs are from Huchra &
Brodie (1987AJ.....93..779H 1987AJ.....93..779H).
* Other IDs are taken from the relevant papers.
Note (G2): Classification as follows:
GC = globular cluster;
gal = background galaxy;
star = Galactic foreground star.
? = also known as S923 (discussed in Section 3.5).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Jan-2012