VII/49 Galaxies and Clusters of Galaxies (CGCG) (Zwicky, 1968)
Catalogue of Galaxies and Clusters of Galaxies, I-VI
Zwicky F., et al.
<Calif. Inst. of Techn., Pasadena, 6 vols. (1961-68)>
=1961CGCG..C......0Z 1961CGCG..C......0Z
ADC_Keywords: Galaxy catalogs
Foreword:
All this documentation file is derived from the
"Documentation for the Machine-Readable Version of the Catalogue of
Galaxies and Clusters of Galaxies: Data on Individual Galaxies"
prepared by Robert S. Hill, NASA Doc. SSD-T-1-5069-0022-82
(November 1982)
Description:
This document describes a machine-readable version of a portion of the
"Catalogue of Galaxies and Clusters of Galaxies" (Zwicky, et al.). The
published catalogue covers 560 Palomar Sky Survey fields, and for each
field it lists both individual galaxies and clusters of galaxies. Its
limiting magnitude for galaxies is approximately +15.5 apparent
photographic magnitude. The present machine-readable version includes
only the individual galaxies. It consists of two files, the first of
which lists the galaxies (data file) and the second of which
enumerates the fields covered (headers file). Note: the abbreviation
ADC used in this document refers to the Astronomical Data Center,
NASA/Goddard Space Flight Center.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
data 25 29363 Data on individual galaxies
headers 36 560 Headers (fields)
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See also:
VII/4 : Zwicky (and Abell) Clusters of Galaxies
VII/190 : Updated version (1996) of the Zwicky Galaxy Catalog
Byte-by-byte Description of file: data
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Bytes Format Units Label Explanations
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1- 4 A4 --- Field [ 0-9AB]+= Field number (1)
7- 8 I2 h RAh Hours RA, 1950.0 of the field center
9- 12 F4.1 min RAm Minutes RA, 1950.0 of the field center
13 A1 --- DE- Sign Dec, 1950.0
14- 15 I2 deg DEd Degrees Dec, 1950.0 of the field center
16- 17 I2 arcmin DEm Minutes Dec, 1950.0 of the field center
19- 22 F4.1 mag Pmag Apparent photographic magnitude (2)
25 I1 --- Rem_Code [1]? '1' if remark in published version (3)
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Note (1): not all the fields surveyed are represented in this file, as
some contain clusters only. The fields coincide with a subset of
Palomar Sky Survey fields but are numbered differently. The records in
this file are sorted in the same order as the corresponding data in
the published catalogue: by field number (ascending), and within each
field by right ascension (ascending).
Note (2): The introduction to vol. 1 of the published catalogue contains
detailed descriptions of the methods of estimation, which can be
summarized as follows: magnitudes down to about 15.2 or 15.5 were
estimated using the Schraffier method on films taken with an 18-inch
Schmidt camera; below this magnitude range, estimates were made
directly from the 48-inch Schmidt plates. The nominal limiting
magnitude of the catalogue is +15.7, but fainter objects may be
present.
Note (3): Remarks include notations such as "diffuse" or "compact."
Numerical data, such as velocities or Harvard magnitudes, are not
taken to be remarks.
Byte-by-byte Description of file: headers
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Bytes Format Units Label Explanations
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1- 4 A4 --- Field [ 0-9AB]+ Field number (1)
6- 7 I2 h RAh Hours RA, 1950.0 of the field center
9- 10 I2 min RAm Minutes RA, 1950.0 of the field center
12 A1 --- DE- Sign Dec, 1950.0
13- 14 I2 deg DEd Degrees Dec, 1950.0 of the field center
16- 17 I2 arcmin DEm Minutes Dec, 1950.0 of the field center
19- 21 I3 --- GalCnt Galaxy count for field (2)
28- 31 A4 --- POSS Palomar Obs. Sky Survey plate number (3)
33- 36 I4 --- MLP [1/1037] Mead-Luyten-Palomar number (4)
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Note (1): All the published fields are represented in this file, with
one record per field, even if the field contains no individual
galaxies.
The field center may be displaced from the corresponding Palomar Sky
Survey plate center by as much as half a degree, but the entire field
is always contained within the corresponding Palomar Sky Survey plate
area. The fields are six by six degrees.
Note (2): This information was generated by computer and is not in the
published catalogue. The following fields contain no individual
galaxies (headers are, however, present in this file):
443 444 489 490 509 510 511 527 528 543
Note (3): This information was derived independently of the published
catalogue by comparison with a Fortran program of center coordinates
to a PSS headers file (see Catalogue: VI/25)
Note (4): This system numbers the PSS fields (including Whiteoak
extension) from 1 ... 1037. The numbers equal the corresponding
Luyten- Palomar (LP) numbers plus 1, except for the north polar
fields, which in the LP system are numbered 1A and 1B; and in the
MLP system, 1 and 2. The LP system comes from the Luyten- Palomar
automated proper motion survey. The MLP numbers are used in
PSS-oriented catalogues developed by the ADC.
Historical Notes:
* November 1982, by Robert S. Hill (Doc. SSD-T-1-5069-0022-82)
This version is based on one supplied to the ADC by M. Hauser
(NASA/GSFC), which consists of six files of card images corresponding
to the six volumes of the published catalogue. For each survey field,
there is a header record and a trailer record, and the data for the
galaxies are in the intervening records, with four galaxies per
record. According to Hauser (private communication), this version may
have been keypunched at the California Institute of Technology in the
early 1970's.
The present version was generated by the following steps:
(1) the information for each galaxy was written to a separate
record, to which the field number was added;
(2) the header and trailer records were deleted, and the headers
were written to a separate file;
(3) using a Fortran program, the headers were compared to data on
the Palomar Sky Survey fields, and the PSS and MLP numbers
were added as appropriate;
(4) the galaxy counts for each field were generated and added to
the headers.
In addition, the following errors were corrected:
(1) thirteen galaxies dropped from field 30 were restored;
(2) the errata published in vols. 2-6 were incorporated as far as
they were relevant, as follows:
Field No. Correction
13 Galaxy 1156.7-0323 became 1158.7-0323.
39 Galaxy 1118.6+0328 added.
41 Galaxy 1212.7+0602 added.
42 Galaxy 1221.1+0720 got remarks flag.
42 Galaxy 1221.2+0728 became 1221.3+0728.
42 Galaxy 1221.5+0719 became 1221.6+0719.
70 Galaxy 1223.7+1314 Lost remarks flag.
70 Galaxy 1223.9+0917 got remarks flag.
70 Galaxy 1228.0+1246 added.
126 Galaxy 1110.8+2226 added.
153 Pmag of galaxy 956.4+3059 became 13.6.
267 Galaxy 1100.0+5629 became 1100.2+5629.
431 Pmag of galaxy 2326.0+1427 became 13.2.
Not all the data on individual galaxies in the original published
catalogue are in this version. In particular, there are no IC or NGC
numbers, velocities, or data from other catalogues. Also,
supplementary data on particular galaxies within the clusters are not
included.
* November 1991: on the "Selected Astronomical Catalogs" Vol. 1 CD-ROM,
directory /nonstell/galaxies/cgcg
* October 1995: documentation standardized at CDS
(End) Francois Ochsenbein [CDS] 02-Oct-1995