J/ApJ/900/95 New M87 GCs metallicities from Keck & MMT sp. (Villaume+, 2020)
The assembly history of M87 through radial variations in chemical abundances of
its field star and globular cluster populations.
Villaume A., Foreman-Mackey D., Romanowsky A.J., Brodie J., Strader J.
<Astrophys. J., 900, 95 (2020)>
=2020ApJ...900...95V 2020ApJ...900...95V
ADC_Keywords: Abundances, [Fe/H]; Clusters, globular; Spectra, optical
Keywords: Galaxy chemical evolution ; Globular star clusters ; Galaxy mergers ;
Galaxy stellar halos ; Galaxy stellar content
Abstract:
We present an extensive study of spectroscopically derived chemical
abundances for M87 and its globular cluster (GC) system. Using
observations from the Mitchell spectrograph at McDonald, LRIS at Keck,
and Hectospec on the MMT, we derive new metallicity gradients from
∼2 to 140kpc. We use a novel hierarchical statistical framework to
simultaneously separate the GC system into subpopulations while
measuring the metallicity gradients of those subpopulations. We create
physically motivated spectral stacks of the GC subpopulations by
leveraging the output of this statistical framework to perform the
first application of abundance tagging in a massive early-type galaxy
to better constrain the origins of the GC subpopulations and thus the
assembly history of M87. We find a metal-poor, α-enhanced
population of GCs in both the inner and outer halos unanticipated by
current cosmological simulations of galaxy evolution. We use the
remarkably flat metallicity gradients we find for both the metal-rich
and metal-poor GC subpopulations in the inner halo as tentative
evidence that some amount of the metal-poor GCs formed directly in the
halo of M87 at high redshift.
Description:
Using updated full-spectrum stellar population synthesis (SPS) models,
we present the first detailed stellar population analysis of M87 and
its globular cluster (GC) system from spectroscopy. We applied the
models to 322 GCs extending from the inner to outer halo.
In Villaume+ (2019ApJ...879...45V 2019ApJ...879...45V) we applied full-spectrum SPS models
to the Keck/LRIS data set of M87 GCs (Strader+ 2011, J/ApJS/197/33) to
obtain estimates of iron metallicity ([Fe/H]) relative to solar. Here,
we do the same analysis for the MMT/Hectospec sample.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 38 317 [Fe/H] measurements for the GCs included in this work
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/120/1841 : Abund. & Kinematics of Halo and Disk Stars (Fulbright 2000)
J/A+A/414/503 : Abundances in the Sgr dSph (Bonifacio+, 2004)
J/A+A/416/1117 : Abundances in the early Galaxy (Cayrel+, 2004)
J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)
J/A+A/440/321 : Chemical abundances in 43 metal-poor stars (Jonsell+, 2005)
J/AJ/132/137 : Abundances of extremely metal-poor stars (Cohen+, 2006)
J/ApJ/645/613 : Abundances of HD 221170 (Ivans+, 2006)
J/AJ/132/1714 : Phot. and Spectroscopic study of TY Gru (Preston+, 2006)
J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)
J/ApJ/681/1524 : Detailed abundances for 28 metal-poor stars (Lai+, 2008)
J/ApJ/681/197 : ACS Virgo Cluster Survey. XV (Peng+, 2008)
J/ApJ/679/1549 : Sp. of metal-poor star CS 17435-00532 (Roederer+, 2008)
J/ApJ/701/1053 : Abundances of 8 stars in the Draco dSph (Cohen+, 2009)
J/ApJS/182/216 : Surface photometry of Virgo ellipticals (Kormendy+, 2009)
J/ApJ/706/1095 : Chemical compositions of 26 outer halo stars (Zhang+, 2009)
J/ApJ/708/560 : Spectroscopy of UMa II and Coma Ber (Frebel+, 2010)
J/ApJ/711/573 : Abundances in a halo stellar stream (Roederer+, 2010)
J/A+A/533/A134 : Abundances of microlensed stars in the Bulge (Bensby+, 2011)
J/MNRAS/414/1227 : Mg/Fe ratio of MILES stars (Milone+, 2011)
J/ApJS/197/33 : The M87 globular cluster system (Strader+, 2011)
J/A+A/548/A34 : Abund. of carbon-enhanced metal-poor stars (Allen+, 2012)
J/MNRAS/420/37 : NGC 4365 globular clusters (Blom+, 2012)
J/ApJ/748/29 : Spectroscopy of M87 globular clusters (Romanowsky+, 2012)
J/MNRAS/426/1475 : CaT in 903 globular clusters (Usher+, 2012)
J/AJ/145/13 : Metal-poor stars from SDSS/SEGUE. I. (Aoki+, 2013)
J/ApJ/778/56 : Hamburg/ESO Survey extremely metal-poor stars (Cohen+, 2013)
J/ApJ/763/61 : Abund. of 7 red giant members of BootesI (Gilmore+, 2013)
J/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxies (Kirby+, 2013)
J/MNRAS/436/1172 : Globular Clusters of NGC 4278 in SLUGGS (Usher+, 2013)
J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)
J/A+A/562/A146 : Chemical abundances of 8 metal-poor stars (Ishigaki+, 2014)
J/ApJ/795/158 : The MASSIVE survey : 116 candidate galaxies (Ma+, 2014)
J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)
J/ApJ/814/121 : CASH project. III. The CEMP star HE0414-0343 (Hollek+, 2015)
J/ApJ/807/171 : SkyMapper Survey metal-poor star sp. (Jacobson+, 2015)
J/ApJ/798/110 : Equivalent widths of LAMOST metal-poor stars (Li+, 2015)
J/MNRAS/451/2625 : SLUGGS Globular Cluster CaT and [Z/H] (Pastorello+, 2015)
J/ApJ/812/109 : HST & Keck spectrosc. of bright CEMP-s stars (Placco+, 2015)
J/A+A/574/A129 : First CEMP star in the Sculptor dSph (Skuladottir+, 2015)
J/ApJ/802/30 : NGVS VI. Ultra-compact dwarfs in M87 (Zhang+, 2015)
J/ApJ/824/42 : Star clusters in M31. VII. GCs RVs (Caldwell+, 2016)
J/MNRAS/460/884 : EMBLA survey. Galactic bulge metal-poor stars (Howes+, 2016)
J/MNRAS/458/105 : SLUGGS NGC 3607 and 3608 globular clusters (Kartha+, 2016)
J/MNRAS/455/820 : M87 globular cluster candidates catalog (Oldham+, 2016)
J/A+A/620/A111 : Confirmed PN in M87 outer regions (Longobardi+, 2018)
J/ApJ/874/66 : MASSIVE. XII. Early-type gal. gradients (Greene+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- [SRB2011] Identifier from Strader+ 2011, J/ApJS/197/33
8- 16 F9.5 deg RAdeg [187.299/188.17] Right Ascension (J2000)
18- 25 F8.5 deg DEdeg [11.9/12.9] Declination (J2000)
27- 31 F5.2 [Sun] [Fe/H] [-1.82/0.42] Metallicity derived in this work
33- 36 F4.2 [Sun] e_[Fe/H] [0.1/0.85] Uncertainty in [Fe/H]
38- 38 I1 --- Inst [0/1] Instrument used (1)
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Note (1): Instrument used as follows:
0 = MMT/Hectospec (145 occurrences);
1 = Keck/LRIS (172 occurrences).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Dec-2021