J/ApJS/256/29 Color-metallicity relations of GCs. X. M87 spec. (Kim+, 2021)
Nonlinear color-metallicity relations of globular clusters.
X. Subaru/FOCAS multiobject spectroscopy of M87 globular clusters.
Kim S., Yoon S.-J., Lee S.-Y., Chung C., Sohn S.T.
<Astrophys. J. Suppl. Ser., 256, 29-29 (2021)>
=2021ApJS..256...29K 2021ApJS..256...29K (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular; Spectra, optical; Radial velocities;
Abundances; Colors
Keywords: cD galaxies; Elliptical galaxies; Lenticular galaxies; Virgo Cluster
Globular star clusters; Dynamical evolution; Stellar kinematics
Stellar dynamics; Galaxy chemical evolution
Abstract:
We obtained spectra of some 140 globular clusters (GCs) associated
with the Virgo central cD galaxy M87 with the Subaru/FOCAS MOS mode.
The fundamental properties of GCs such as age, metallicity, and
α-element abundance are investigated by using simple stellar
population models. It is confirmed that the majority of M87 GCs are as
old as, more metal-rich than, and more enhanced in α-elements
than the Milky Way GCs. Our high-quality, homogeneous data set enables
us to test the theoretical prediction of inflected color-metallicity
relations (CMRs). The nonlinear-CMR hypothesis entails an alternative
explanation for the widely observed GC color bimodality, in which even
a unimodal metallicity spread yields a bimodal color distribution by
virtue of nonlinear metallicity-to-color conversion. The newly derived
CMRs of old, high-signal-to-noise-ratio GCs in M87 (the V-I CMR of
83 GCs and the M-T2 CMR of 78 GCs) corroborate the presence of the
significant inflection. Furthermore, from a combined catalog with the
previous study on M87 GC spectroscopy, we find that a total of 185 old
GCs exhibit a broad, unimodal metallicity distribution. The results
corroborate the nonlinear-CMR interpretation of the GC color
bimodality, shedding further light on theories of galaxy formation.
Description:
The spectroscopic globular cluster (GC) targets are selected from the
photometric data on the M87 GC candidates obtained with Suprime-Cam on
the 8.2m Subaru telescope (Tamura+ 2006MNRAS.373..588T 2006MNRAS.373..588T and
2006MNRAS.373..601T 2006MNRAS.373..601T).
We performed spectroscopy on a total of 157 M87 GC candidates with the
Multi-Object Spectrography (MOS) mode of the Faint Object Camera and
Spectrograph (FOCAS) on the Subaru telescope on 2007 March 16-19
(spectral coverage of 3700-6000Å with R∼800).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 42 130 Radial velocity measurements of M87 globular
clusters (GCs)
table3.dat 199 130 Lick indices for GCs in M87
table4.dat 160 130 Lick index measurement uncertainties for M87 GCs
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See also:
VII/195 : Globular Clusters in the Milky Way (Harris, 1996)
VII/202 : Globular Clusters in the Milky Way (Harris, 1997)
J/AJ/105/1762 : Globular clusters around NGC 1399 (Ostrov+ 1993)
J/AJ/106/493 : Globular clusters in M87 (Lee+, 1993)
J/ApJS/111/377 : Hγ & Hδ absorption features (Worthey+ 1997)
J/ApJS/116/1 : Old Stellar Populations. VI. Absorption-Line (Trager+ 1998)
J/AJ/115/1801 : VRI photometry of M87 globular clusters (Harris+ 1998)
J/ApJ/513/733 : Globular cluster system in M87 (Kundu+, 1999)
J/ApJ/559/812 : Globular cluster system in M87 (Hanes+, 2001)
J/ApJ/613/279 : ACS Virgo Cluster Survey. III. M87 (Jordan+, 2004)
J/ApJ/621/673 : Line indices for 124 early-type galaxies (Thomas+, 2005)
J/AJ/131/866 : Hot populations in M87 globular clusters (Sohn+, 2006)
J/MNRAS/382/1947 : CT1 photometry in NGC 1399 and NGC 4486 (Forte+, 2007)
J/ApJ/674/857 : Radial velocities and CT1 magnitudes in M60 galaxy (Lee+, 2008)
J/MNRAS/386/1443 : 2dF study of globular clusters in NGC 5128 (Beasley+, 2008)
J/ApJS/180/54 : GC candidates in ACS Virgo survey. (Jordan+, 2009)
J/ApJ/703/42 : HST photometry of M87 globular clusters (Peng+, 2009)
J/ApJ/708/1335 : Spectroscopy of globulars in NGC 5128 (Woodley+, 2010)
J/AJ/140/2101 : NGC 5128 globular clusters photometry (Sinnott+, 2010)
J/AJ/141/61 : Star clusters in M31. II. (Caldwell+, 2011)
J/ApJ/743/149 : Color-metallicity relations. II. M87 GCs (Yoon+, 2011)
J/ApJS/197/33 : The M87 globular cluster system (Strader+, 2011)
J/ApJ/746/88 : HST observations of GCs in NGC 1399 (Blakeslee+, 2012)
J/ApJ/748/29 : Spectroscopy of M87 globular clusters (Romanowsky+, 2012)
J/MNRAS/428/389 : SLUGGS globular clusters in early-type galaxies (Pota+, 2013)
J/ApJ/768/137 : HST photometry of M84 globular clusters (Yoon+, 2013)
J/MNRAS/446/369 : Colour & spectral index from the SLUGGS survey (Usher+, 2015)
J/A+A/574/A21 : Isolated elliptical galaxies and GC (Richtler+, 2015)
J/MNRAS/455/820 : M87 globular cluster candidates catalog (Oldham+, 2016)
J/MNRAS/458/105 : SLUGGS NGC 3607 and 3608 globular clusters (Kartha+, 2016)
J/ApJ/835/212 : Wide-field spec. survey of GCs in Virgo cluster (Ko+, 2017)
J/AJ/156/6 : Light element abund. of RGB & AGB stars in M10 (Gerber+, 2018)
J/ApJ/900/95 : New M87 GCs metallicities from Keck & MMT sp. (Villaume+, 2020)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- ID Identifier
7- 14 F8.5 h RAhour Right Ascension in decimal hours (J2000)
16- 23 F8.5 deg DEdeg Declination in decimal degrees (J2000)
25- 29 F5.2 mag Vmag [18.64/22.37] Apparent Johnson V band
Vega magnitude
31- 34 F4.2 mag V-I [0.89/1.35] The Johnson (V-I) color index
36- 42 F7.2 km/s RVel [259.5/2034] Radial velocity
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- ID Identifier
7- 14 F8.4 0.1nm HdA [-11.3/10.9]? Lick HδA Balmer index (1)
16- 22 F7.4 0.1nm HdF [-5.8/5.8]? Lick HδF Balmer index (1)
24- 30 F7.4 mag CN1 [-0.42/0.53]? Lick CN1 metal index
32- 38 F7.4 mag CN2 [-0.9/0.6]? Lick CN2 metal index
40- 46 F7.4 0.1nm Ca4227 [-2/30.6]? Lick Ca4227 metal index (1)
48- 54 F7.4 0.1nm G4300 [-5.6/11]? Lick G4300 metal index (1)
56- 63 F8.4 0.1nm HgA [-10.01/5.7]? Lick HγA Balmer index (1)
65- 71 F7.4 0.1nm HgF [-4.53/4.53]? Lick HγF Balmer index (1)
73- 80 F8.4 0.1nm Fe4383 [-16.2/10.15]? Lick Fe4383 metal index (1)
82- 88 F7.4 0.1nm Ca4455 [-1.8/14.4]? Lick Ca4455 metal index (1)
90- 96 F7.4 0.1nm Fe4531 [-3.7/5.3]? Lick Fe4531 metal index (1)
98-104 F7.4 0.1nm C24668 [-6/13.7]? Lick C2 4668 metal index (1)
106-112 F7.4 0.1nm Hb [-0.65/3.3]? Lick Hβ Balmer index (1)
114-120 F7.4 0.1nm Fe5015 [-1.22/7] Lick Fe5015 metal index (1)
122-128 F7.4 mag Mg1 [-0.081/0.24]? Lick Mg1 metal index
130-135 F6.4 mag Mg2 [0.019/0.44]? Lick Mg2 metal index
137-143 F7.4 0.1nm Mgb [-2.11/6.05] Lick Mgb metal index (1)
145-151 F7.4 0.1nm Fe5270 [-1.26/4.4]? Lick Fe5270 metal index (1)
153-159 F7.4 0.1nm Fe5335 Lick Fe5335 metal index (1)
161-167 F7.4 0.1nm Fe5406 Lick Fe5406 metal index (1)
169-175 F7.4 0.1nm Fe5709 Lick Fe5709 metal index (1)
177-183 F7.4 0.1nm Fe5782 ? Lick Fe5782 metal index (1)
185-191 F7.4 [Sun] [Fe/H] [-2.5/0.03]? Metallicity
193-199 F7.4 [Sun] [M/H] [-2.17/-0.0026]? Our empirically derived
metallicity
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Note (1): In units of Angstroms.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- ID Identifier
7- 12 F6.4 0.1nm e_HdA [0.6/7.31]? Lick HδA Balmer index
uncertainty (1)
14- 19 F6.4 0.1nm e_HdF ? Lick HδF Balmer index uncertainty (1)
21- 26 F6.4 mag e_CN1 ? Lick CN1 metal index uncertainty
28- 33 F6.4 mag e_CN2 ? Lick CN2 metal index uncertainty
35- 41 F7.4 0.1nm e_Ca4227 ? Lick Ca4227 metal index uncertainty (1)
43- 48 F6.4 0.1nm e_G4300 ? Lick G4300 metal index uncertainty (1)
50- 55 F6.4 0.1nm e_HgA ? Lick HγA Balmer index uncertainty (1)
57- 62 F6.4 0.1nm e_HgF ? Lick HγF Balmer index uncertainty (1)
64- 69 F6.4 0.1nm e_Fe4383 ? Lick Fe4383 metal index uncertainty (1)
71- 76 F6.4 0.1nm e_Ca4455 ? Lick Ca4455 metal index uncertainty (1)
78- 83 F6.4 0.1nm e_Fe4531 ? Lick Fe4531 metal index uncertainty (1)
85- 90 F6.4 0.1nm e_C24668 ? Lick C2 4668 metal index uncertainty (1)
92- 97 F6.4 0.1nm e_Hb ? Lick Hβ Balmer index uncertainty (1)
99-104 F6.4 0.1nm e_Fe5015 Lick Fe5015 metal index uncertainty (1)
106-111 F6.4 mag e_Mg1 ? Lick Mg1 metal index uncertainty
113-118 F6.4 mag e_Mg2 ? Lick Mg2 metal index uncertainty
120-125 F6.4 0.1nm e_Mgb Lick Mgb metal index uncertainty (1)
127-132 F6.4 0.1nm e_Fe5270 ? Lick Fe5270 metal index uncertainty (1)
134-139 F6.4 0.1nm e_Fe5335 Lick Fe5335 metal index uncertainty (1)
141-146 F6.4 0.1nm e_Fe5406 Lick Fe5406 metal index uncertainty (1)
148-153 F6.4 0.1nm e_Fe5709 ? Lick Fe5709 metal index uncertainty (1)
155-160 F6.4 0.1nm e_Fe5782 ? Lick Fe5782 metal index uncertainty (1)
--------------------------------------------------------------------------------
Note (1): In units of Angstroms.
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Acknowledgements:
Marion Schmitz [zb4ms at ipac.caltech.edu]
History:
From electronic version of the journal
* 02-Mar-2022: Insert into VizieR
* 28-Jul-2022: Description updated for Table 2: RA coordinates are
in decimal hours and not in decimal degrees. The CDS is thankful to
Marion Schmitz for this catch!
References:
Yoon et al. Paper I. 2006Sci...311.1129Y 2006Sci...311.1129Y
Yoon et al. Paper II. 2011ApJ...743..149Y 2011ApJ...743..149Y Cat. J/ApJ/743/149
Yoon et al. Paper III. 2011ApJ...743..150Y 2011ApJ...743..150Y
Yoon et al. Paper IV. 2013ApJ...768..137Y 2013ApJ...768..137Y Cat. J/ApJ/768/137
Kim et al. Paper V. 2013ApJ...768..138K 2013ApJ...768..138K
Chung et al. Paper VI. 2016ApJ...818..201C 2016ApJ...818..201C
Kim et al. Paper VII. 2017ApJ...843...43K 2017ApJ...843...43K
Lee et al. Paper VIII. 2019ApJS..240....2L 2019ApJS..240....2L
Lee et al. Paper IX. 2020ApJ...905..124L 2020ApJ...905..124L
Kim et al. Paper X. 2021ApJS..256...29K 2021ApJS..256...29K This catalog
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 31-Jan-2022