A Catalogue of Rich Clusters of Galaxies
Abell, G. O., Corwin, H. G. Jr., and Olowin, R. P. 1988,
Astrophys. J. Suppl., submitted.
The content of the Abell Catalogue data files is identical to the tables
published in Ap. J. Suppl. Series. There are four data files:
nabell.fin: final northern Abell catalogue
rich.fin: final southern Abell catalogue
poor.fin: supplementary southern Abell catalogue
sabell.fin northern Abell clusters found during the southern survey
and all have exactly the same format. An example with column headings is
given below. Note that the northern Abell catalogue does not list xcen, ycen,
Abell type, m1, m3, m10, previous listings, or number of plates and observers.
The northern catalogue has also had all known errors corrected (Struble and
Rood (1987ApJS...63..543S), Leir (1976, M.Sc. Thesis, Toronto Univ.) as reported
by Struble and Rood (1987ApJS...63..543S), and Corwin 1972
unpublished).
EXPLANATION OF THE TABLES:
Column Contents
Abell Running number ("Abell" number) in order of right ascension for
1855 as listed by Abell (1958ApJS....3..211A) for the northern
clusters (1 to 2712) and in order of right ascension for 1950 for
the southern clusters (2713 to 4076). The supplementary southern
clusters are numbered from S1 to S1174.
Position Right Ascension and Declination for 1950 of the apparent cluster
(1950) center. When the cluster was found in more than one field, a
mean position is listed. Abell and Corwin used overlays
positioned with respect to SAO stars to estimate the position,
while Olowin calculated positions from his measured rectangular
coordinates. Thus, Olowin's positions were given double weight
when means were taken.
Field The Southern Sky Survey Field number in which the cluster is
located. For clusters found in two or more fields, the field
given is the one in which the cluster is closest to the plate
center.
xcen, ycen Rectangular coordinates in millimeters of the apparent cluster
center, referred to the CENTER of the Southern Sky Survey Field
given in the previous column. The field centers are defined by
the crosses near the edges of the plates. The positive x
direction is to the east (left) and the positive y direction is
to the north (top). These are in the same sense as the
rectangular coordinates given by Lauberts (1983, Cat. VII/34) in
the ESO/Uppsala Catalogue, and are listed to facilitate location
of the cluster on the 5 x 5-degree ESO 1.0-m Schmidt portion of
the Southern Sky Survey. Abell and Corwin measured rectangular
coordinates from the left and bottom edges of the plates, so
the xcen and ycen from their data are calculated assuming that
the plate center is 164 millimeters from the left and bottom
crosses on the plates (they also measured the crosses). Olowin
referred his rectangular coordinates directly to the plate center
as defined by the crosses, so no transformation is necessary for
his data.
Abell Type Cluster classification in Abell's system: I = irregular, R =
regular, IR and RI = intermediate. ":" indicates a mean type
with differences between estimates of two steps, or an uncertain
type estimate; "?" indicates a mean type with differences
between estimates of three steps, or a questionable type
estimate.
Bautz-Morgan Classification in the Bautz-Morgan system (Bautz and Morgan
Type 1970ApJ...162L.149B). ":" indicates a mean type with differences
between estimates of two steps, or an uncertain type estimate; "?"
indicates a mean type with differences between estimates of three
or more steps, or a questionable type estimate. For the
northern Abell catalogue, these types are primarily from Leir
and van den Bergh (1977ApJS...34..381L). Other sources for the
northern catalogue are Bautz and Morgan (1970ApJ...162L.149B),
Bautz (1972AJ.....77....1B), Corwin (1974AJ.....79.1356C),
Kristian et al. (1978ApJ...221..383K), Sandage et al.
(1976ApJ...205..688S), and White (1978ApJ...226..591W).
Count Number of cluster members between m3 and m3+2, corrected for
background contamination using the "universal" luminosity
function from Rainey (1976, Ph.D. Univ. California, Los Angeles).
The southern counts are corrected to the system of the northern
catalogue (see text).
m1 Weighted mean total V magnitude estimate for the first-ranked
cluster member. NO GALACTIC EXTINCTION CORRECTION HAS BEEN
APPLIED. ":" indicates a mean magnitude with a standard
deviation of more than +-0.5 mag, or an uncertain magnitude
estimate. "?" indicates a mean magnitude with a standard
deviation of more than +-1.0 mag, or a questionable magnitude
estimate. "*" indicates that the magnitude estimate is for a
known or probable foreground object.
m3 Weighted mean total V magnitude estimate for the third-ranked
cluster member, again UNCORRECTED for galactic extinction.
Uncertainty symbols as for m1.
m10 Weighted mean total V magnitude estimate for the tenth-ranked
cluster member, again UNCORRECTED for galactic extinction.
Uncertainty symbols as for m1 and m3.
Position RA and Dec of the apparent cluster center precessed to the
(2000) equinox of 2000.
Previous Sources of previous listings:
Listings B = Braid and MacGillivray (1978MNRAS.182..241B),
D = Duus and Newell (1977ApJS...35..209D),
d = Dressler (1980ApJS...42..565D, Cat. VII/174),
K = Klemola (1969AJ.....74..804K),
O = Olowin (1987, in IAU Symposium 124, p. 331),
Q = Quintana and White (1980BAAS...12..834Q and
private communication),
R = Rose (1976A&AS...23..109R),
S = Sersic (1974Ap&SS..28..365S), and
s = Snow (970AJ.....75..237S).
Even though all questionable cases of cross identification were
checked on the Southern Sky Survey, there remain a few uncertain
cases. These are given in the Notes to the Catalogue.
xll, yll Rectangular coordinates of the apparent cluster center, referred
to the south-east (lower left) edge of the Southern Sky Survey
Field given in the first line. The field edges are defined by
the crosses near the edges of the plates; thus, it is possible
for these coordinates to be negative. For the northern Abell
catalogue, these coordinates are from Rood and Sastry
(1971PASP...83..313R). Olowin's data were transformed assuming
that the plate center is 164 millimeters from the crosses.
l and b Galactic coordinates of the apparent cluster centers,
calculated from the 1950 equatorial coordinates.
z Cluster redshift from the lists by Struble and Rood
(1987ApJS...63..555S, northern Abell clusters), Huchra's 1986
collection of published redshifts (Huchra, private communication),
Fairall (1985, Cape Town Univ., Astronomy Department Publ. 7),
Corwin (1981, Ph.D. Thesis, Univ. Edinburgh; see also Corwin
and Emerson 1982MNRAS.200..621C), Couch and Newell
(1984ApJS...56..143C and private communication), Noonan
(1981ApJS...45..613N), and Spinrad (private communication).
The redshift is in parentheses if it is more than 0.3 dex from the
expected redshift for the cluster's m10. Redshifts from Huchra's
list and from Fairall (1985, Cape Town Univ. Publ. 7) were
determined by selecting all galaxies with known redshifts within
one Abell radius of the cluster center, rejecting discordant
redshifts, and averaging the remainder.
R Richness class as defined by Abell (1958ApJS....3..211A). For the
northern Abell catalogue, this is Abell's original richness class.
D Distance class corresponding to Abell's (1958ApJS....3..211A)
criteria. For the northern Abell catalogue, this is Abell's
original distance class from his m10. For the southern catalogue,
these are from the m10A's listed in the next column.
m10A Magnitude for the tenth-ranked cluster member in Abell's
(1958ApJS....3..211A) system, corrected for galactic extinction
following Abell's formula. For the northern Abell catalogue,
this is Abell's original magnitude. For the southern catalogue,
these were transformed from the m10 on the first line (see text).
Number and Number of fields in which the cluster was found, and the
Observers observer's initial (A = Abell, C = Corwin, O = Olowin).