J/ApJS/173/643 GALEX UV photometry of M31 Globular Clusters (Rey+, 2007)
GALEX ultraviolet photometry of globular clusters in M 31: three-year results
and a catalog.
Rey S.-C., Rich R.M., Sohn S.T., Yoon S.-J., Chung C., Yi S.K., Lee Y.-W.,
Rhee J., Bianchi L., Madore B.F., Lee K., Barlow T.A., Forster K.,
Friedman P.G., Martin D.C., Morrissey P., Neff S.G., Schiminovich D.,
Seibert M., Small T., Wyder T.K., Donas J., Heckman T.M., Milliard B.,
Szalay A.S., Welsh B.Y.
<Astrophys. J. Suppl. Ser., 173, 643-658 (2007)>
=2007ApJS..173..643R 2007ApJS..173..643R
ADC_Keywords: Clusters, globular ; Photometry, ultraviolet
Keywords: galaxies: individual (M31) - galaxies: star clusters -
globular clusters: general - ultraviolet: galaxies
Abstract:
We present ultraviolet (UV) photometry of M31 globular clusters (GCs)
found in 23 Galaxy Evolution Explorer (GALEX) images covering the
entirety of M31. We detect 485 and 273 GCs (and GC candidates) in the
near-ultraviolet (NUV) and far-ultraviolet (FUV), respectively. The UV
properties of GCs have been analyzed using various combinations of
UV-optical and optical-optical colors. Comparing M31 data with
those of Galactic GCs in the UV with the aid of population models, we
find that the age ranges of old GCs in M31 and the Galactic halo are
similar. Three metal-rich ([Fe/H]>-1) GCs in M31 produce significant
FUV flux making their FUV-V colors unusually blue for their
metallicities. These are thought to be analogs of the two peculiar
Galactic GCs, NGC 6388 and NGC 6441, with extended blue HB stars. We
detect 12 (10) intermediate-age GC candidates in NUV (FUV) identified
by previous spectroscopic observations. On the basis of comparing our
UV photometry to population models, we suggest that some of
spectroscopically identified intermediate-age GCs may not be truly
intermediate in age, but rather older GCs that possess developed HB
stars which contribute to enhanced UV flux as well as Balmer lines.
Description:
The M31 images were obtained as part of the Nearby Galaxy Survey (NGS)
carried out by GALEX in two UV bands: FUV (135-175nm) and NUV
(175-275nm). Details on the early observations of 14 fields released
under the GALEX Release 1 (GR1) can be found in Thilker et al.
(2005ApJ...619L..67T 2005ApJ...619L..67T) and Paper I (Rey et al., 2005ApJ...619L.119R 2005ApJ...619L.119R).
We have observed an additional nine GALEX fields in 2004
September-November, which are included in the GALEX Release 2 (GR2).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 144 501 UV and optical photometry of M31 globular
clusters and candidates
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See also:
J/AJ/119/727 : M31 globular clusters photometry (Barmby+, 2000)
J/AJ/122/2458 : M31 globular clusters from HST (Barmby+, 2001)
J/A+A/416/917 : M31 globular clusters Revised Bologna Catalog (Galleti+ 2004)
J/A+A/449/143 : Photometry of M31 globular cluster candidates (Ma+, 2006)
J/A+A/483/769 : HST VI photometry of 3 GC in M31 (Fuentes-Carrera+ 2008)
J/MNRAS/392/L55 : M31 GC clusters Kmag + structural param. (Peacock+ 2009)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- RBC Revised Bologna Catalog identification
(Cat. J/A+A/416/917)
8- 15 A8 --- [BHB2000] Barmby et al. (2000, Cat. J/AJ/119/727)
identification
17- 27 A11 --- NEDname The NED identification
29 I1 --- Q [1,3] RBC classification quality flag (1)
31- 32 I2 h RAh Hour of Right Ascension (J2000)
34- 35 I2 min RAm Minute of Right Ascension (J2000)
37- 41 F5.2 s RAs Second of Right Ascension (J2000)
43 A1 --- DE- Sign of the Declination (J2000)
44- 45 I2 deg DEd Degree of Declination (J2000)
47- 48 I2 arcmin DEm Arcminute of Declination (J2000)
50- 53 F4.1 arcsec DEs Arcsecond of Declination (J2000)
55- 60 F6.3 mag NUV ? GALEX NUV band (175-275nm) magnitude (2)
62- 66 F5.3 mag e_NUV ? Error in NUVmag
68- 73 F6.3 mag FUV ? GALEX FUV band (135-175nm) magnitude (2)
75- 79 F5.3 mag e_FUV ? Error in NUVmag
81- 85 F5.2 mag Umag ? RBC U band magnitude
87- 91 F5.2 mag Bmag ? RBC B band magnitude
93- 97 F5.2 mag Vmag ? RBC V band magnitude
99-103 F5.2 mag Rmag ? RBC R band magnitude
105-109 F5.2 mag Imag ? RBC I band magnitude
111-115 F5.2 mag Jmag ? RBC J band magnitude
117-121 F5.2 mag Hmag ? RBC H band magnitude
123-127 F5.2 mag Kmag ? RBC K band magnitude
129-133 F5.2 [-] [Fe/H] ? Barmby et al. (2000, Cat. J/AJ/119/727)
metallicity
135-138 F4.2 [-] e_[Fe/H] ? Error in [Fe/H]
140-144 F5.2 km/s Res ? Morrison et al. (2004ApJ...603...87M 2004ApJ...603...87M)
kinematic velocity residual
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Note (1): The class is:
1 = confirmed GC;
2 = candidate cluster;
3 = uncertain candidate.
Note (2): As shown in Figure 1, each GALEX image overlaps with at least
another image. For objects that lie in these overlapping fields, we
have listed their mean magnitudes weighted by their photometric errors.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 28-May-2009