J/ApJ/824/42 Star clusters in M31. VII. Globular clusters RVs (Caldwell+, 2016)
Star clusters in M31.
VII. Global kinematics and metallicity subpopulations of the globular clusters.
Caldwell N., Romanowsky A.J.
<Astrophys. J., 824, 42-42 (2016)>
=2016ApJ...824...42C 2016ApJ...824...42C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Radial velocities ; Abundances, [Fe/H] ;
Galaxies, nearby
Keywords: galaxies: individual: M31; galaxies: star clusters: general;
Local Group
Abstract:
We carry out a joint spatial-kinematical-metallicity analysis of
globular clusters (GCs) around the Andromeda Galaxy (M31), using a
homogeneous, high-quality spectroscopic data set. In particular, we
remove the contaminating young clusters that have plagued many
previous analyses. We find that the clusters can be divided into three
major metallicity groups based on their radial distributions: (1) an
inner metal-rich group ([Fe/H]>-0.4); (2) a group with intermediate
metallicity (with median [Fe/H]=-1); and (3) a metal-poor group, with
[Fe/H]. The metal-rich group has kinematics and spatial properties
like those of the disk of M31, while the two more metal-poor groups
show mild prograde rotation overall, with larger dispersions --in
contrast to previous claims of stronger rotation. The metal-poor GCs
are the least concentrated group; such clusters occur five times less
frequently in the central bulge than do clusters of higher
metallicity. Despite some well-known differences between the M31 and
Milky Way GC systems, our revised analysis points to remarkable
similarities in their chemodynamical properties, which could help
elucidate the different formation stages of galaxies and their GCs. In
particular, the M31 results motivate further exploration of a
metal-rich GC formation mode in situ, within high-redshift, clumpy
galactic disks.
Description:
Our M31 GC sample is based on high signal-to-noise spectra from the
MMT/Hectospec during the years 2004-2007. Paper II (Caldwell+, 2011,
J/AJ/141/61) determined metallicities using iron-dominated Lick
indices as measured on Hectospec spectra. Those same spectra supplied
the velocities used here, supplemented by even more accurate
velocities measured in the high dispersion spectra of Strader et al.
(2011AJ....142....8S 2011AJ....142....8S).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 441 All known globular clusters in our M31 sample
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See also:
V/143 : Revised Bologna Catalog of M31 clusters, V.5 (Galleti+ 2012)
VII/195 : Globular Clusters in the Milky Way (Harris, 1996)
J/AJ/148/4 : JHK photometry of 913 globular clusters in M31 (Wang+, 2014)
J/ApJ/769/10 : Spectroscopy of M31 globular clusters (Jacoby+, 2013)
J/AJ/146/135 : Physical param. of 29 M31 globular clusters (Agar+, 2013)
J/A+A/549/A60 : Ages and [Fe/H] of M31 globular clusters (Cezario+, 2013)
J/A+A/544/A155 : HST photometry of M31 globular clusters (Federici+, 2012)
J/MNRAS/426/975 : Kinematics of NGC 2768 from PNe (Forbes+, 2012)
J/ApJ/758/133 : Metallicity of M31 HII regions & PNe (Sanders+, 2012)
J/AJ/143/14 : Lick indices of M31 globular clusters (Schiavon+, 2012)
J/A+A/531/A155 : HST photometry in six M31 globular clusters (Perina+, 2011)
J/AJ/141/61 : Star clusters in M31. II. (Caldwell+, 2011)
J/MNRAS/402/803 : M31 globular cluster system (Peacock+, 2010)
J/AJ/139/1438 : SED & age estimates of M31 globular clusters (Wang+, 2010)
J/A+A/508/1285 : Metallicity of M31 globular clusters (Galleti+, 2009)
J/A+A/507/1375 : HST/ACS VI data of M31 globular clusters (Perina+, 2009)
J/AJ/137/94 : Star clusters in M31 (Caldwell+, 2009)
J/AJ/133/2764 : M31 globular clusters structural parameters (Barmby+, 2007)
J/A+A/471/127 : Revised Bologna Catalog of M31 clusters, V.3 Galleti+, 2007)
J/A+A/456/985 : Radial velocities of M31 candidate clusters (Galleti+, 2006)
J/AJ/123/2490 : RV & [Fe/H] of M31 globular cluster system (Perrett+, 2002)
J/AJ/119/727 : M31 globular clusters photometry (Barmby+, 2000)
J/AcA/48/455 : Globular Clusters in M31 and M33 (Mochejska+, 1998)
http://www.cfa.harvard.edu/oir/eg/m31clusters/M31_Hectospec.html : M31
Hectospec page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object identifier
12- 13 I2 h RAh [0/23] Hour of Right Ascension (J2000)
15- 16 I2 min RAm Minute of Right Ascension (J2000)
18- 22 F5.2 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- [+] Sign of Declination (J2000)
25- 26 I2 deg DEd [31/48] Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 34 F4.1 arcsec DEs Arcsecond of Declination (J2000)
36- 41 F6.1 km/s RVel [-713/70.5]? Radial velocity
43- 46 F4.1 km/s e_RVel [0.2/40]? Uncertainty in RVel
48- 50 A3 --- r_RVel Reference code for RVel (1)
52- 55 F4.1 [-] [Fe/H] [-2.8/0.4]? Metallicity
57- 59 F3.1 [-] e_[Fe/H] [0.1/0.9]? Uncertainty in [Fe/H] (2)
61- 63 A3 --- r_[Fe/H] Reference code for [Fe/H] (1)
66- 69 F4.1 Gyr Age [4.8/14] Age from paper II
(Caldwell+, 2011, J/AJ/141/61)
70 A1 --- u_Age [:] Uncertainty flag on Age
72- 74 F3.1 [Msun] LogM [2/7.2]? Log total mass (3)
76- 80 F5.1 kpc R [0.1/141] Radial distance to M31 center
82- 86 F5.1 kpc Ra [0.2/409] Semi-major axis radius (4)
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Note (1): Reference as follows:
b = Barmby et al. (2000, J/AJ/119/727);
co = Colucci et al. (2014ApJ...797..116C 2014ApJ...797..116C);
p = Perrett et al. (2002, J/AJ/123/2490);
hs2 = Hectospec from paper II (Caldwell+, 2011, J/AJ/141/61;
118 RVel and 303 [Fe/H]);
hs7 = Hectospec from here (13 RVel and 15 [Fe/H]);
he = Hectochelle from Strader et al. (2011AJ....142....8S 2011AJ....142....8S; 204 RVel);
hx = Huxor et al. (2014MNRAS.442.2165H 2014MNRAS.442.2165H) and references therein;
rbc = Galleti et al. (2009, J/A+A/508/1285).
c = derived from PHAT colors (Caldwell et al. 2016 in prep);
co = Colucci et al. (2014ApJ...797..116C 2014ApJ...797..116C);
m06 = CMD value from Mackey et al. (2006ApJ...653L.105M 2006ApJ...653L.105M);
m07 = CMD value from Mackey et al. (2007ApJ...655L..85M 2007ApJ...655L..85M);
m13 = CMD value from Mackey et al. (2013MNRAS.429..281M 2013MNRAS.429..281M);
pa = CMD value from Huxor et al. (2014MNRAS.442.2165H 2014MNRAS.442.2165H);
ph = CMD value from PHAT data, (Caldwell et al. 2016 in prep);
p11 = Perina et al. (2011, J/A+A/531/A155);
r05 = CMD value from Rich et al. (2005AJ....129.2670R 2005AJ....129.2670R);
Left blanck where no Hectospec spectroscopy or HST CMD exists, and
PHAT photometry is not available.
Note (2): Minimum uncertainties set to 0.1.
Note (3): From photometry in paper II (Caldwell+, 2011, J/AJ/141/61) or here.
Note (4): The semimajor axis radius Ra is defined in Equation (1) as:
Ra=R[(1+(q2-1)cos2φ)0.5]/q
where R is the distance to the galaxy center (taken to be
RA=00:42:44.3, DE=+41:16:09.4, J2000), q=0.3, the ratio of the
assumed axes, and φ is the angle the cluster makes with respect
to the major axis and the center. See section 3.
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History:
From electronic version of the journal
References:
Caldwell et al. Paper I. 2009AJ....137...94C 2009AJ....137...94C Cat. J/AJ/137/94
Caldwell et al. Paper II. 2011AJ....141...61C 2011AJ....141...61C Cat. J/AJ/141/61
Morrison et al. Paper III. 2011ApJ...726L...9M 2011ApJ...726L...9M
Schiavon et al. Paper IV. 2012AJ....143...14S 2012AJ....143...14S Cat. J/AJ/143/14
Strader et al. Paper V. 2011AJ....142....8S 2011AJ....142....8S
Schiavon et al. Paper VI. 2013ApJ...776L...7S 2013ApJ...776L...7S
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 10-Aug-2016