VII/84A Groups of Galaxies. III. The CfA Survey (Geller+ 1983)
Groups of Galaxies. III. The CfA Survey Geller M.J., Huchra J.P. <Astrophys. J. Suppl. Ser. 52, 61 (1983)> =1983ApJS...52...61G
ADC_Keywords: Clusters, galaxy ; Galaxy catalogs Description: The catalog contains statistically homogeneous groups of galaxies based on the Harvard-Smithsonian Center for Astrophysics (CfA) redshift survey. Groups in the catalog are all density enhancements in redshift space of a factor greater than 20. All groups contain at least three members. There are 176 groups in the catalog and 102 groups have been identified in one or more previous studies. The catalog includes group numbers, numbers of members, equatorial coordinates, mean flow-corrected galactocentric velocities, line-of-sight-velocity dispersion, integrated group magnitudes, crossing times for the groups, and mean harmonic radii of the groups. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file groups.dat 45 176 CfA redshift survey data for 176 galaxy groups (Table1 of paper) crossid.dat 37 196 Comparison against previous catalogs (Table3 of paper)
See also: VII/86 : Groups of Galaxies. I. (Huchra & Geller 1982) VII/164 : The CfA Redshift Catalogue, Version Nov. 1993 (Huchra+, 1993) Byte-by-byte Description of file: groups.dat
Bytes Format Units Label Explanations
1- 3 I3 --- GrpNum [1/176]+ Group running number 4- 7 I4 --- NumGal Number of Galaxies composing this group 8- 10 I3 h RAh Right Ascension (1950) hours 11- 14 F4.1 min RAm RA in minutes 16 A1 --- DE- Sign of Declination 17- 18 I2 deg DEd Declination (1950) in degrees 19- 20 I2 arcmin DEm DEC in arcminutes 21- 25 I5 km/s GCvel *GC velocity 26- 30 I5 km/s Vdisp *LOS vel. disp. 31- 35 F5.1 mag GrpMag Integrated group magnitude 36- 40 F5.2 --- H*xTime *Crossing time 41- 45 F5.2 Mpc Mradius *Mean harmonic radius
Note on GCvel: Mean flow-corrected galactocentric velocity in km/sec. Note on Vdisp: Line-of-sight velocity dispersion, uncorrected for measurement error, in km/sec. Note on H*xTime: Crossing time of the group in units of 1/H. This field was mislabeled in Geller and Huchra (1983) (see History). Note on Mradius: Mean harmonic radius of the group as defined by equation (13) of Huchra and Geller (1982), in Mpc. This field was mislabeled in Geller and Huchra (1983) (see Remarks and Modifications).
Byte-by-byte Description of file: crossid.dat
Bytes Format Units Label Explanations
1- 3 I3 --- GrpNum [1/176]+= Catalog number of the group 5- 9 A5 --- TGnum *TG number(s) 11- 12 I2 --- HGnum ? Huchra and Geller (1982ApJ...257..423H) 15- 16 I2 --- DVnum ? de Vaucouleurs (1975) group number 20- 37 A18 --- Alias Other names of groups in this cluster
Note on TGnum: Corresponding TG group (Turner and Gott =1976ApJS...32..409T), if any. This may be a range; for example, 50-57 for GOGIII group 94.
Remarks and Modifications: The (GOGIII) 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 two text files of data from Tables 1 and 3 in the published catalog Huchra and Geller (1982). Blank columns were removed from Table 1 using an editor to reduce the record size from 54 to 45 bytes. The character "-", used in Table 3 to indicate no data, was changed to a blank, so that most of the fields could be read with a FORTRAN integer format. No other changes were made in either file. A FORTRAN program was run to check the validity of each field according to its data type and value. In the original published catalog (Geller and Huchra 1983) the crossing time and mean harmonic radius fields were mislabeled (erratum, Geller and Huchra 1984). We wish to thank J. P. Huchra for bringing this to our attention. The second file, crossid.dat, contains a table comparing the present catalog against three earlier catalogs: DV = de Vaucouleurs (1975); HG = Huchra and Geller (1982); TG = Turner and Gott (1976) Acknowledgements: The original ADC documentation by Anne C. Raugh (1987) was used to create this ReadMe file. References: Geller, M. J. and Huchra, J. P. =1983ApJS...52...61G (Erratum in ApJS 54, 442) Huchra, J. P. and Geller, M. J. =1982ApJ...257..423H Turner, E. L. and Gott, J. R. =1976ApJS...32..409T de Vaucouleurs, G. 1975, in Stars and Stellar Systems, Galaxies and the Universe, Vol. 9, ed. A. Sandage, M. Sandage, and J. Kristian (Chicago: University of Chicago Press), p. 557.
(End) C.-H. Joseph Lyu [Hughes STX/NASA] 12-Dec-1995
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