ADC/CDS Standard Document for Catalog:/journal_tables/AJ/122/2458/
ADC/CDS Standard Document for Catalog:| 1. Use the ADC Data Viewer Suite to visualize the data. |
|
| 2. Get the data files via anonymous FTP. (See Note.) |
|
J/AJ/122/2458 M31 globular clusters from HST (Barmby+, 2001)
================================================================================
M31 globular clusters in the Hubble Space Telescope archive.
I. Cluster detection and completeness.
Barmby P., Huchra J.P.
<Astron. J. 122, 2458 (2001)>
=2001AJ....122.2458B
================================================================================
ADC_Keywords: Clusters, globular
Keywords: galaxies: individual (M31) - galaxies: star clusters
Abstract:
Globular clusters at the distance of M31 have apparent angular sizes
of a few arcseconds. While many M31 globular clusters have been
detected and studied from ground-based images, the high spatial
resolution of the Hubble Space Telescope (HST) allows much more robust
detection and characterization of star cluster properties. We present
the results of a search of 157 HST Wide Field Planetary Camera 2
images of M31. We found 82 previously catalogued globular cluster
candidates, as well as 32 new globular cluster candidates and 20 open
cluster candidates. We present images of the new candidates and
photometry for all clusters. We assess existing cluster catalogs'
completeness and use the results to estimate the total number of
globular clusters in M31 as 460+/-70. The specific frequency is
S_N_=1.2+/-0.2 and the mass specific frequency T=2.4+/-0.4; these
values are at the upper end of the range seen for spiral galaxies.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 45 154 HST fields Used in the search
table2.dat 62 68 Catalogued objects that are not M31 globular clusters
table3.dat 76 52 New globular cluster candidates found in M31 HST
fields
table4.dat 62 129 Photometry of new clusters and candidates in M31
--------------------------------------------------------------------------------
See also:
J/A+AS/116/447 : M31 globulars clusters ellipticities (Staneva+, 1996)
J/AJ/114/1488 : Globulars in M31 (Holland+ 1997)
J/other/AcA/48.455 : Globular Clusters in M31 and M33 (Mochejska+, 1998)
J/AJ/119/727 : M31 globular clusters photometry (Barmby+, 2000)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Hour of Right Ascension (J2000)
4- 5 I2 min RAm Minute of Right Ascension (J2000)
7- 11 F5.2 s RAs Second of Right Ascension (J2000)
13 A1 --- DE- Sign of the Declination (J2000)
14- 15 I2 deg DEd Degree of Declination (J2000)
17- 18 I2 arcmin DEm Arcminute of Declination (J2000)
20- 23 F4.1 arcsec DEs Arcsecond of Declination (J2000)
25- 29 A5 --- Filt Filter used in observation
31- 34 I4 s Exp Combined exposure of all images
36- 44 A9 --- Name Dataset name
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Catalog object name, as in Barmby et al.,
2000, Cat. <J/AJ/119/727>
11- 21 A11 --- Class Object classification (1)
23- 61 A39 --- HST The HST field(s) image name(s)
--------------------------------------------------------------------------------
Note (1): Object classification:
pr: Objects which have slightly larger FWHMs than most stars,
although we still believe them to be stars.
stars: Objects which appear to be blended images of 2 or 3 stars.
blank: Object which was not detected at its catalog coordinates.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 20 A20 --- Name Cluster designation,
M31GC JHHMMSS+DDMMSS or M31OC JHHMMSS+DDMMSS
22- 23 I2 h RAh Right ascension (J2000)
25- 26 I2 min RAm Right ascension (J2000)
28- 32 F5.2 s RAs Right ascension (J2000)
34 A1 --- DE- Declination sign (J2000)
35- 36 I2 deg DEd Declination (J2000)
38- 39 I2 arcmin DEm Declination (J2000)
41- 44 F4.1 arcsec DEs Declination (J2000)
46- 48 A3 --- Qual [ABCD/ ] Globular cluster probability code (1)
51- 76 A26 --- Com Comments and possible identification
--------------------------------------------------------------------------------
Note (1): Probability of globular cluster nature:
A, B: High-probability globular cluster candidates
(A: very likely to be a globular cluster)
C, D: Low-probability globular cluster candidates
(D: likely not a globular cluster)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 20 A20 --- Name Cluster name (1)
22- 27 F6.3 mag Umag ? The integrated U band magnitude
28 A1 --- f_Umag [*] Indicates a F300W instead of standard
U-band magnitude
30- 35 F6.3 mag Bmag ? The integrated B band magnitude
37- 42 F6.3 mag Vmag ? The integrated V band magnitude
44- 49 F6.3 mag Rmag ? The integrated R band magnitude
51- 56 F6.3 mag Imag ? The integrated I band magnitude
58- 61 F4.2 arcsec Rad1/2 The half-light radius
--------------------------------------------------------------------------------
Note (1): Names:
[BHB2000] NNNNNN: Name as in Barmby et al., 2000, Cat. <J/AJ/119/727>
Nbol NN: Name as in Barmby et al., 2000, Cat. <J/AJ/119/727>
M31GC JHHMMSS+DDMMSS or M31OC JHHMMSS+DDMMSS: Name from table3.dat
--------------------------------------------------------------------------------
History:
From electronic version of the journal
================================================================================
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 22-Jan-2002