J/AJ/119/727 M31 globular clusters photometry (Barmby+, 2000)
M31 globular clusters: colors and metallicities
Barmby P., Huchra J.P., Brodie J.P., Forbes D.A., Schroder L.L.,
Grillmair C.J.
<Astron. J. 119, 727 (2000)>
=2000AJ....119..727B 2000AJ....119..727B
ADC_Keywords: Clusters, globular ; Photometry, UBVRIJKLMNH ; Radial velocities ;
Abundances, [Fe/H]
Keywords: galaxies: individual (M31) - galaxies: star clusters -
globular clusters: general
Abstract:
We present a new catalog of photometric and spectroscopic data on M31
globular clusters (GCs). The catalog includes new optical and
near-infrared photometry for a substantial fraction of the 435
clusters and cluster candidates. We use these data to determine the
reddening and intrinsic colors of individual clusters, and we find
that the extinction laws in the Galaxy and M31 are not significantly
different. There are significant (up to 0.2 mag in V-K) offsets
between the clusters' intrinsic colors and simple stellar population
colors predicted by population synthesis models; we suggest that these
are due to systematic errors in the models. The distributions of M31
clusters' metallicities and metallicity-sensitive colors are bimodal,
with peaks at [Fe/H]~-1.4 and -0.6. The distribution of V-I is often
bimodal in elliptical galaxies' globular cluster systems, but it is
not sensitive enough to metallicity to show bimodality in M31 and
Galactic cluster systems. The radial distribution and kinematics of
the two M31 metallicity groups imply that they are analogs of the
Galactic "halo" and "disk/bulge" cluster systems. The globular
clusters in M31 have a small radial metallicity gradient, suggesting
that some dissipation occurred during the formation of the globular
cluster system. The lack of correlation between cluster luminosity and
metallicity in M31 GCs shows that self-enrichment is not important in
GC formation.
Objects:
----------------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------------
00 42 44.3 +41 16 09 M 31 = NGC 224
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 99 435 Catalog of photometric data for M31 globular clusters
table2.dat 38 199 M31 cluster candidates shown not to be clusters
refs.dat 45 41 References to table1 and table2
table3.dat 80 285 New photometric data for M31 globular clusters
table5.dat 38 61 New spectroscopic data for M31 globular clusters
--------------------------------------------------------------------------------
See also:
J/A+AS/116/447 : M31 globulars clusters ellipticities (Staneva+, 1996)
J/AJ/114/1488 : Globulars in M31 (Holland+ 1997)
J/AcA/48/455 : Globular Clusters in M31 and M33 (Mochejska+, 1998)
J/AJ/122/2458 : M31 globular clusters from HST (Barmby+, 2001)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Name (G1)
10 A1 --- l_Vmag Limit flag on Vmag
11- 15 F5.2 mag Vmag ? V magnitude
17- 21 F5.2 mag B-V ? B-V colour index
23- 27 F5.2 mag U-B ? U-B colour magnitude
29- 33 F5.2 mag V-R ? V-R colour magnitude
35- 39 F5.2 mag V-I ? V-I colour magnitude
41- 45 F5.2 mag Jmag ? J magnitude
47- 51 F5.2 mag Hmag ? H magnitude
53- 57 F5.2 mag Kmag ? K magnitude
59- 74 A16 --- r_mag Optical source (1)
76- 79 A4 --- r_I-R I-R source (1)
81-100 A20 --- Com Comments (1)
--------------------------------------------------------------------------------
Note (1): Multiple references for optical photometry sources are given
in order, for each individual filter or color. HRI indicates cluster
confirmed by high resolution imaging, HRS indicates published
high-resolution spectroscopy, CMD indicates published color-magnitude
diagram. N205 indicates that object may possibly belong to NGC 205.
See refs.dat file for reference numbers.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Name (G1)
15- 31 A17 --- Class Classification
34- 38 A5 --- r_Class References in table refs.dat
--------------------------------------------------------------------------------
Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Ref Reference code
6- 24 A19 --- BibCode Bibcode
26- 45 A20 --- Aut Author's name
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Name (G1)
10- 14 F5.2 mag Vmag ? V magnitude
16 I1 0.01mag e_Vmag ? rms uncertainty on Vmag
18- 22 F5.2 mag B-V ? B-V colour index
24 I1 0.01mag e_B-V ? rms uncertainty on B-V
27- 31 F5.2 mag U-B ? U-B colour index
33- 34 I2 0.01mag e_U-B ? rms uncertainty on U-B
37- 41 F5.2 mag V-R ? V-R colour index
43- 44 I2 0.01mag e_V-R ? rms uncertainty on V-R
46- 50 F5.2 mag V-I ? V-I colour index
52- 53 I2 0.01mag e_V-I ? rms uncertainty on V-I
56- 60 F5.2 mag Jmag ? J magnitude
62 I1 0.01mag e_Jmag ? rms uncertainty on Jmag
65- 69 F5.2 mag Kmag ? K magnitude
71- 72 I2 0.01mag e_Kmag ? rms uncertainty on Kmag
75- 79 A5 --- Com Comments (1)
--------------------------------------------------------------------------------
Note (1): Comments:
"ID" indicates objects with uncertain identifications.
"ac" indicates objects near bright stars.
These objects' magnitudes were measured in small apertures and
corrected to the standard aperture using growth curves.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- cluster [cn] c: cluster, n: non-cluster
3- 11 A9 --- Name Name (G1)
13- 17 I5 km/s RV Radial velocity
19- 20 I2 km/s e_RV rms uncertainty on RV
22- 26 F5.2 Sun [Fe/H] ? Metallicity
28- 31 F4.2 Sun e_[Fe/H] ? rms uncertainty on [Fe/H]
33- 38 A6 --- Com Comments
--------------------------------------------------------------------------------
GLobal notes:
Note (G1): Names in Simbad:
[BHB2000] for names as NNN-NNN, NNNA-NNN, NNN-ANNN and NNN-AANN
[CCS85] for names as DAONNN
BA 1-NNN for names as BA NNN
NBol NN for names as NBNN
--------------------------------------------------------------------------------
History: From AJ electronic version
(End) James Marcout, Patricia Bauer [CDS] 27-Mar-2000