VII/85A Hickson Compact Groups of Galaxies (Hickson 1982)
Systematic Properties of Compact Groups of Galaxies
Hickson P.
<Astrophys. J., 255, 382 (1982)>
=1982ApJ...255..382H 1982ApJ...255..382H
ADC_Keywords: Clusters, galaxy - 215 ; Galaxy catalogs - 330
Description:
The catalog is a list of 100 compact groups of galaxies identified by
a systematic search of the Palomar Observatory Sky Survey red prints.
Each group contains four or more galaxies, has an estimated mean
surface brightness brighter than 26.0 magnitude per arcsec and
satisfies an isolation criterion. The catalog includes running
numbers, equatorial coordinates, group types according to the two
brightest members, number of galaxies in the group, angular diameters
of the smallest circles containing the geometric centers of all group
members, total magnitudes (red) of those galaxies counted as group
members, estimated red magnitudes of the brightest galaxies in the
groups, corrected redshifts of the brightest galaxies, and other
designations of the groups.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
data.dat 72 100 The catalog of Compact Groups of Galaxies
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See also:
J/ApJ/380/30 : LF of Compact Groups (Mendes de Oliveira+ 1991)
J/ApJ/399/353 : Radial velocities in Hickson Compact Groups (Hickson+ 1992)
J/A+AS/117/39 : Far-IR properties of Hickson Compact Groups (Allam+, 1996)
Byte-by-byte Description of file: data.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- HRC [1/100]+ Number of the group in this catalog
5- 6 I2 h RAh Equatorial coordinates 1950 Right Ascension
7- 8 I2 min RAm Right Ascension minutes
9-10 I2 s RAs Right Ascension seconds
12 A1 --- DE- Declination sign
13-14 I2 deg DEd Declination degrees (1950)
15-16 I2 arcmin DEm Declination arcminutes
17-18 I2 arcsec DEs [0,60] Declination arcseconds
20-21 A2 --- Type *Type
22-23 I2 --- MCount *Member count
24-28 F5.1 arcmin AngSize *Angular size
29-33 F5.1 mag TotMag *Total magnitude
34-38 F5.1 mag Bmag *Brightest member magnitude
39-44 F6.3 --- Rshift *? Redshift
46-51 A6 --- Aname1 *Alternate name 1
53-58 A6 --- Aname2 *Alternate name 2
60-65 A6 --- Aname3 *Alternate name 3
67-72 A6 --- Aname4 *Alternate name 4
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Note on Type:
Two-character code (a letter followed by a number)
classifying the group according to its two brightest members:
S The brightest galaxy is a spiral galaxy.
E The brightest galaxy is not a spiral galaxy.
1 m(b) - m(a) ≥ 1.0
2 0.5 ≤ m(b) - m(a) < 1.0
3 m(b) - m(a) < 0.5
where m(a) and m(b) are the estimated red magnitudes of the brightest
and second brightest members, respectively, of the cluster.
Note on MCount:
Number of galaxies in the group. Only those galaxies within three
magnitudes of the brightest galaxy are counted as members.
Note on AngSize:
Angular diameter, in arcminutes, of the smallest circle containing the
geometric centers of all group members.
Note on TotMag:
Total estimated red magnitude of those galaxies counted as group members
(see member count, above.)
Note on Bmag:
Estimated red magnitude of the brightest galaxy in the group, in units
of magnitude.
Note on Rshift:
Corrected redshift of the brightest galaxy. In all but ten cases this
field is blank.
Note on Aname1, Aname2, Aname3, Aname4:
Other designations of the group, if any (at most, four).
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Remarks and Modifications:
The (SPCGG) was received by the Astronomical Data Center (ADC), NASA
Goddard Space Flight Center, from the Centre de Donnees Astronomiques,
Strasbourg (CDS), in December 1986.
The original tape consisted of a single text file containing the
catalog data from Table 1 of Systematic Properties of Compact Groups
of Galaxies, in a slightly more compact format. ADC personnel deleted
eight blank columns from the end of each record in the file to reduce
the record size from 80 to 72 bytes and ran a FORTRAN program to check
the validity of each field according to its data type and value. Two
minor typographic errors discovered in the computer-readable version
were then corrected by referring to the published catalog. A possible
error was also detected, but not changed, in record number 97, where
the DEC seconds field contains a value of 60 (this value appears in
the printed version).
P. Hickson kindly supplied a list of errata including some corrections
in addition to the published erratum. This list is reproduced below;
the indicated changes have already been made to the catalog data.
ERRATUM
HCG AngSize TotMag Bmag
14 6.7 12.1 13.0
22 5.0 10.5 11.1
60 2.3 13.4 14.4
69 1.9 12.2 13.1
82 3.1 12.2 13.1
HCG RAh/RAm/RAs DEd/DEm/DEs
03 00 31 39 -07 52 07
31 04 59 08 -04 19 42
74 15 17 14 +21 04 27
89 21 17 34 -04 07 17
AngSize angular size of the group
TotMag total magnitude of the group
Bmag magnitude of the brightest member
References:
Hickson, P., 1982, Astrophys. J., 255, 382
(Erratum 1982, Astrophys. J., 259, 930).
(End) C.-H. Joseph Lyu [Hughes STX/NASA] 16-Oct-1995