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VII/26D Uppsala General Catalogue of Galaxies (UGC) (Nilson 1973)
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Uppsala General Catalogue of Galaxies (UGC)
Nilson P.
=1973ugcg.book.....N (SIMBAD/NED BibCode)
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ADC_Keywords: Galaxy catalogs
Description:
The Uppsala General Catalogue of Galaxies (UGC) is an essentially
complete catalogue of galaxies to a limiting diameter of 1.0' and/or
to a limiting apparent magnitude of 14.5 on the blue prints of the
Palomar Observatory Sky Survey (POSS). Coverage is limited to the sky
north of declination -02.5degrees. Galaxies smaller than 1.0' in
diameter but brighter than 14.5 mag may be included from the Catalogue
of Galaxies and of Clusters of Galaxies (CGCG, Zwicky et al.
1961-1968); all such galaxies in the CGCG are included in the UGC. The
galaxies are ordered by 1950 right ascension.
The catalogue contains descriptions of the galaxies and their
surrounding areas, plus conventional system classifications and
position angles for flattened galaxies. Galaxy diameters on both the
blue and red POSS prints are included and the classifications and
descriptions are given in such a way as to provide as accurate an
account as possible of the appearance of the galaxies on the prints.
Only the data portion of the published UGC is included in the
machine-readable version.
The order of the records is strictly by UGC number; i.e., the Addenda
records follow their main catalogue counterparts in the file. The
colons (indicating uncertainty) and various other codes (parentheses,
brackets) are not included in the machine-readable version of the
catalogue. Several possible improvements to the catalogue might
consist of adding codes corresponding to the published version, a
second file containing abbreviations and terminology and a third file
with the extensive notes. It would also be important to add an
asterisk or some other code to data records having a note in the
proposed third file.
This document describes the machine-readable version of the UGC as
distributed by the Astronomical Data Centers. It is intended to enable
users to read and process the data without problems or guesswork. For
additional details regarding the classifications, measurement of
apparent magnitudes, and data content, the source reference should be
consulted. A copy of this document should accompany any
machine-readable copy of the catalogue.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 81 12940 UGC catalogue
errors.dat 42 134 The changes made by the ADC in 1995
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Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- UGCtext "UGC"
5- 9 I5 --- UGC [1/12921]+= UGC number
10 A1 --- A [A] "A" if the galaxy is from the Addenda
list of the published catalogue;
otherwise blank.
11- 12 I2 h RAh Right Ascension 1950 (hours)
13- 16 F4.1 min RAm Right Ascension 1950 (minutes)
17 A1 --- DE- Declination 1950 (sign)
18- 19 I2 deg DEd Declination 1950 (degrees)
20- 21 I2 arcmin DEm Declination 1950 (minutes)
22- 34 A13 --- MCG MCG designation (1)
35- 38 I4 --- POSS Number of the POSS field in which the
galaxy is best visible.
39- 44 F6.2 arcmin MajAxis ? Major axis of the galaxy as measured on
the POSS blue print. (2)
45- 49 F5.2 arcmin MinAxis ? Minor axis of the galaxy as measured on
the POSS blue print. (2)
50- 52 I3 deg PA [0/180[? Position angle measured in the
conventional manner from North through
East. (3)
53- 59 A7 --- Hubble Classification in the Hubble system or
remarks, in a free field format,
including lower case designations.
61- 64 F4.1 mag Pmag ? Photographic magnitude mpg , recorded to
precision given in published catalogue;
i.e., if tenths not reported, byte 64 is
blank.
65- 69 I5 km/s RadVel ? Radial velocity corrected for Solar
motion (4)
70- 75 F6.2 arcmin aR ? Major axis of the galaxy as measured on
the POSS red print. (2)
76- 80 F5.2 arcmin bR ? Minor axis of the galaxy as measured on
the POSS red print. (2)
81 I1 --- i [0/7]? Inclination to the line of sight for
spirals (5)
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Note (1): The Morphological Catalogue of Galaxies (MCG)
(Vorontsov-Velyaminov et al. 1962, 1963, 1964, 1968). The first number
of the designation is the Palomar Observatory Sky Survey (POSS) 6deg
zone, from the equator +00 to the north celestial pole +15; the second
number is the POSS field along the zone, while the third number is the
galaxy in this field in the MCG. Non-MCG galaxies are assigned the
number 000 in the third position, but the first and second values are
given correctly.
Note (2): The precision to which diameters are recorded matches the
published catalogue; additional decimal places are blank, but colons,
brackets and parentheses are not included in the computerized
catalogue.
Note (3): Colons, parentheses and brackets in the published catalogue
are not included here. Blank if data not present.
Note (4): Radial Velocity is relative to the Local Group according to
V0 = 300 cos A, where A is the distance to the conventional Solar
apex at lI=55deg, bI=0deg or lII = 87deg bII = +1deg. If the
uncertainties in the measurements were considered too large to make
corrections meaningful, usually only the uncorrected value is given.
Note (5): Inclination measured on a scale from 1 (face-on) to 7 (edge-on).
For galaxies of high inclination, a value is calculated from the
Hubble formula n - 10(a-b)/a [a - major axis, b - minor axis]. The
value 7 denotes objects inclined not more than a few degrees to the
line of sight.
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Byte-by-byte Description of file: errors.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ID Number of entry
6 A1 --- IDs Suffix for entry number
7- 9 A3 --- field Field in error
11- 20 A10 --- old Old entry
22- 42 A21 --- new New entry and comments
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Historical Notes:
The magnetic tape version of the Uppsala General Catalogue of Galaxies
was received from Dr. Robert S. Dixon of the Ohio State University
Radio Observatory on 7 December 1981. As received, the catalogue
consisted of 12,942 logical records of length 90 bytes. Each logical
record contained a sequential counter on bytes 85-90, while bytes
81-84 and single columns throughout the records were not used. There
was also only a five-byte allowance for the major axis of the galaxy
as measured on the red POSS print, a field too small to accommodate
U00454 (M31), which has a major axis of 200:' (in order to fit the
200' value, the radial velocity had been moved left one byte, thus
making it read -2990 km/sec instead of the correct value of -299
km/sec). The following modifications were made to the catalogue to fix
the above items, correct several errors, and to maximize storage
efficiency. Except for item 10, these modifications were made by Francois
Ochsenbein at the CDS.
1.The published edition contains 12,921 objects in the main catalogue
and 19 addenda; hence, with 12,942 records on the tape there were
obviously a few duplicates. The records for UGC 3944 and UGC 6063A
were found to be repeated and the duplicates were deleted.
2.A check for the addenda objects resulted in the discovery of a missing
A for UGC 7399A--this was added.
3.Upon examination of the original file version of the catalogue
supplied to him, Mr. Marion Schmitz discovered the misnumbering of UGC
12417 and UGC 12418 as UGC 12447 and UGC 12448--these errors were
corrected.
4.The data record for UGC 253 was found to have a hexadecimal code "AA"
character (equivalent to a down-arrow in the classification field (bytes
46-52) in place of a lower case "b" (Sb/SB(down-arrow) instead of
Sb/SBb)--this was corrected.
5.The data field for the major axis as measured on the red POSS print
was expanded to six bytes and the record for UGC 454 (discussed above)
corrected.
6.All superfluous blanks were removed to decrease the logical record
length from 90 bytes to 74 bytes (counting also the removal of the
sequential numbers originally in bytes 85-90).
7.UGC and MCG catalog designations were altered to their present format,
extending the record length to 81 bytes.
8.(Version C, made at CDS, August 1993)
a. The error reported by Carlo Giovanardi in "ADC Newsletter" 2.2
(April 1993) was corrected (RAh column)
b. The position of the minor axis blue in UGC 326 which was shifted
has been fixed.
c. All records with radial velocities larger than 10000 km/s expanded
over the red major axis column; the + sign in column 65 was
therefore removed for the following galaxies:
UGC 262 UGC 545 UGC 1095 UGC 4093 UGC 5408 UGC 6514
UGC 8058 UGC 8327 UGC 8696 UGC 8811 UGC 8825 UGC 9509
UGC 10099 UGC 10170 UGC 10180 UGC 10188 UGC 10189 UGC 10191
UGC 10192 UGC 10199 UGC 10635 UGC 11130 UGC 11763 UGC 12397
d. UGC Number 20016 should be read 12016
Position angles for UGC 153, 341 and 388 were corrected
(S. Nishimura, on 30-Aug-1993)
9.(Version D, made at CDS September 1995, following comments by
Ralph Pass ), typo errors in UGC numbers:
4500 5228 5258 7307 10374 10377 10848 11718 11748 12342 12392
12847 12848 12817 12818 12843 12873
10.At least one error may have been corrected inappropriately. UGC5206 and
5854A are both given as MGC+02-28-002 but UGC 5206 is at RA=0941.7
while the MGC galaxy is at RA=1041.7. 5854A is at that location. It
was assumed that these referred to the same galaxy. Hence UGC5854A
was deleted and the RA changed for UGC5206 by the undersigned.
She also moved two records which were out of order to the proper position.
Acknowledgments:
The present version includes a few corrections inserted by CDS (see
Remarks, Modifications, points 8 and 9) compared to the CD-ROM
"Selected Astronomical Catalogs Volume 1" edited by the
Astronomical Data Center, NASA, 1992. It also contains a number of
corrections inserted by the undersigned. The latter are listed in
errors.dat.
Points 8 and 9, the "File Summary" and the
"Byte-by-byte Description" were prepared by Francois Ochsenbein of
the CDS. The file errors.dat and minor modifications to this
acknowledgment were prepared by the undersigned. Otherwise, the
documentation herein is from Wayne H. Warren Jr. (1982).
The latter expressed appreciation to Dr. R. S. Dixon for supplying the
original tape version of the UGC, and to Mr. M. Schmitz for pointing
out the errors that he discovered in the UGC numbers (point 3 above).
Nancy G. Roman expresses appreciation particularly to Mark Anderson
who did an extensive analysis of the catalog. Others errors were
reported by Ralph Pass, Carlo Giovanardi, and James Himer. All have
been checked and most reported errors were correct as reported.
References:
Nilson, P. 1973, Uppsala General Catalogue of Galaxies, Uppsala
Astron. Obs. Ann. 6.
Vorontsov-Velyaminov, B. A., Krasnogorskaya, A. and Arhipova, V. P.
1962-1968, Morphological Catalogue of Galaxies, 4 Volumes (Moscow:
Sternberg Institute 32, 33, 34, 38).
Warren, W.H. Jr 1982, "Documentation for the Machine-Readable Version
of the Uppsala General Catalogue of Galaxies", NSSDC/WDC-A-R&S 82-30,
National Aeronautics and Space Administration, Goddard Space Flight
Center, Greenbelt, Maryland 20771
Zwicky, F. et al. 1961-1968, Catalogue of Galaxies and of Clusters of
Galaxies, I-VI (Pasadena: California Institute of Technology).
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(End) Nancy Grace Roman [ADC/SSDOO] 20-Oct-1995