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ABELLZCAT - Abell Clusters Measured Redshifts Catalog

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Overview

The all-sky ACO (Abell, Corwin and Olowin 1989, ApJS, 70, 1) Catalog of 4073 rich clusters of galaxies and 1175 southern poor or distant S-clusters has been searched for published redshifts. Data for 1059 of them were found and classified into various quality classes, e.g. to reduce the problem of foreground contamination of redshifts. Taking the ACO selection criteria for redshifts, a total of 992 entries remain, 21 percent more than ACO. Redshifts for rich clusters are now virtually complete out to a redshift z of 0.05 in the north and of 0.04 in the south. In the north, the magnitude-redshift (m_10 - z) relation agrees with that of Kalinkov et al. (1985, Astr. Nachr., 306, 283). For the southern rich clusters, minor adjustments to the m_10 - z relation of ACO are suggested, while for the S-clusters the redshifts are about 30 percent lower than estimated.

Catalog Bibcode

1991lssp.conf..279

References

A Catalogue of Measured Redshifts of Abell Clusters of Galaxies
    Andernach H.
   <ASP Conf. Ser. 15, 279 (1991)>
   =1991lssp.conf..279A
A Catalog of Rich Clusters of Galaxies
    Abell, G.O., Corwin, H.G.Jr., Olowin, R.P.
   <Astrophys. J. Suppl. 70, 1 (1989)>
   =1989ApJS...70....1A

Provenance

This table was created by the HEASARC in May 2010 based on CDS Catalog VII/165A file catalog.dat.

Parameters

Name
The Abell Cluster designation using the recommended CDS Dictionary of Nomenclature of Celestial Objects nomenclature for such objects, viz., using a prefix of 'ACO' for the 4076 rich (A-) clusters and a prefis of 'ACO S' for the 1174 supplementary (S-) clusters which are poor or distant clusters not fulfilling the Abell criteria.

RA
The Right Ascension of the center of the cluster of galaxies in the selected equinox. This was given in B1950.0 equatorial coordinates to a precision of 0.1 minutes of time in the original table. The source of the positions is ACO, including revisions by Struble and Rood (1987, ApJS, 63, 555).

Dec
The Declination of the center of the cluster of galaxies in the selected equinox. This was given in B1950.0 equatorial coordinates to a precision of 1 arcminute in the original table. The source of the positions is ACO, including revisions by Struble and Rood (1987, ApJS, 63, 555).

LII
The Galactic Longitude of the center of the cluster of galaxies.

BII
The Galactic Latitude of the center of the cluster of galaxies.

Abell_Richness_Class
A number [0,5] which indicates the Abell richness class of the cluster of galaxies, this being a number characterizing the number of galaxies in the cluster that are no more than 2 magnitudes fainter than the third brightest galaxy cluster member: a higher number indicates more galaxies, i.e., a richer cluster, as follows:

  0 means 30-49 member galaxies
  1 means 50-79 member galaxies
  2 means 80-129 member galaxies
  3 means 130-199 member galaxies
  4 means 200-299 member galaxies
  5 means > 299 member galaxies
  

Abell_Distance_Class
A number [0,7] which indicates the Abell distance class of the cluster of galaxies, this being a number roughly characterizing the distance of the cluster based on the brightness of the tenth brightest galaxy cluster member, where a higher number indicates fainter and more distant clusters of galaxies, as follows:

      * Group 1: mag 13.3-14.0
      * Group 2: mag 14.1-14.8
      * Group 3: mag 14.9-15.6
      * Group 4: mag 15.7-16.4
      * Group 5: mag 16.5-17.2
      * Group 6: mag 17.3-18.0
      * Group 7: mag > 18.0
  

Bautz_Morgan_Class
A number [1,5] which indicates the Bautz-Morgan class of the cluster of galaxies, this being a measure of the contrast in brightness between the brightest member of the cluster and the other cluster members, where a low number of 1 means a very bright centrally dominant (cD) galaxy and a high number of 5 indicates that there is no cD galaxy. The classification scheme was introduced in Bautz and Morgan (1970, ApJ, 162, 149) as a Roman numeral scheme (I, II and III) and the author of the present catalog has rendered it as integers (Andernach 2010, private communicaion), as follows:

    1 means I
    2 means I-II
    3 means II
    4 means II-III
    5 means III
  
Some of the B-M classes were taken from Ciardullo et al. (1985, ApJ, 293, 69).

Bautz_Morgan_Flag
This parameter is a flag [:?] indicates a quality code of the Bautz-Morgan class, where a colon indicates a mean type, with differences between estimates of 2 steps, or an uncertain type estimate, and a question mark indicates a mean type, with differences between estimates of 3 or more steps, or a questionable type estimate.

Mag_10
The magnitude of the 10th brightest cluster member. This magnitude is on the southern scale (m10_S) whenever such a value was given by ACO (i.e. for almost all clusters south of B1950 Declination of -17 degrees, and on the northern scale (m10_N) for all other clusters. Note that the scale of mag_10 (whether S or N) CANNOT be recovered from the present list, but only from the full ACO catalogue (CDS Catalog VII/110, available as the ABELL table in Browse). Since these scales are significantly different, no attempt should be made (based on the mag_10-values of the present list alone) for an all-sky fit to an mag_10-z relation.

Redshift_Flag
This flag parameter [:*!?f] indicates a quality code for the redshift, as follows:

  (blank) = z measured and within a factor of 2 of the mag_10-estimate.
        : = z measured and within a factor of 2 to 4 of the mag_10-estimate.
        * = z measured but outside the above range. Likely due to foreground or
              background object (rejected for mag_10-z relation)
        ! = listed redshift is average of very discordant ones, indicating
              possible line-of-sight projection of clusters
              (not used for mag_10-z relation)
        ? = listed redshift is single peripheral object, concordant within a
              factor of 2 from estimate (not used for mag_10-z relation)
        f = cluster is known from published notes to have foreground galaxies.
              Listed redshift likely due to these objects.
              (rejected for mag_10-z relation)
  
THESE QUALITY CODES MUST BE TAKEN INTO ACCOUNT FOR ANY STATISTICAL ANALYSES (cf. Muriel et al. 1990, AJ 100, 339, Figs 1a and 1b!) The numbers of galaxies contributing to the redshifts (not listed here) is an important quality factor and will be included in a future version of this compilation (Andernach, in preparation).

Redshift
The galactocentric redshift of the cluster of galaxies, on a galactocentric scale as far as the original publications allowed.

Ref_Redshift
The value of this flag indicates the reference from which the redshift value was obtained, as follows:

  A=Abell,Corwin,Olowin89, ApJS 70,1 760   m=Metcalfe et al. 89, MNRAS 236,207  2
  B=Barbon+Capaccioli 86, A&AS 64,503  3   N=Kirshner et al. 87, PASP 99, 1261  4
  b=Bothun et al. 1985, AJ 90, 2487    3   n=Maia,daCosta,Latham 89,ApJS 68,809 1
  C=Colless & Hewett 87 MNRAS 127,847 14   o=Fabricant et al. 89,  ApJ 336, 77  1
  c=Cristiani et al. 1987, AA 179,108  1   O=Owen, White, Thronson 88, AJ 95,1 11
  D=Dressler & Shectman 88, AJ 95,985 12   p=Giovanelli & Haynes 89, AJ 97,633  1
  d=daCosta et al. 1989, AJ 97, 315   13   q=Struble & Rood 1987, ApJS 63, 543 34
  E=Dressler 1980, ApJS 42, 565        0   R=Rhee & Katgert 1988, AAS 72, 243  29
  e=Danziger & Goss 83, MNRAS 202,703  1   S=Shectman 1985, ApJS 57, 77         4
  F=Fairall & Jones 88, Pub.Ast.Dept.      s=Schmidt 1986, Astr.Nachr. 307, 69 30
    Univ.CapeTown 10(6229ent/130refs) 88   T=Cheng & Fang 1987, MNRAS  226,485  2
  f=Focardi et al. 1986, AA 161, 217   1   t=Carter & Teague 84, ProcASA 5,502  2
  G=Giovanelli et al. 86, AJ 92, 250   2   U=Unger et al. 1989, MNRAS 236, 425  6
  g=deGrijp+87,A&AS 70,95; Nat 314,240 5   V=Wasilewski 1983, ApJ 272, 68       3
  H=Hill et al. 1988, ApJ 332, L23     1   v=Leech et al. 1988, MNRAS 237, 977  2
  h=Hill et al. 1988,  AJ 95, 1031     1   W=West 1977, A&AS 27, 73             1
  i=Ciardullo et al. 1985, ApJ 293,69  2   w=West & Frandsen 81, A&AS 44,329    1
  j=Carico et al. 1986, AJ 92, 1254    1   X=combination of  F  and  U          1
  K=Kowalski et al. 1987, AJ 93, 1350  4   x=combination of  f  and  M          1
  k=Kirshner et al. 87, ApJ 314, 493   3   Y=combination of  E  and  U          1
  l=Kopylov et al.84, Astr.Tsirk.1344  4   y=combination of  d  and  n          1
  L=Lewis et al. 1985, ApJS 59, 161    1   z=combination of  E  and  A          1
  M=Michel & Huchra 88, PASP 100,1423  0                              Total= 1059
  

Abell_Radius
The Abell radius of the cluster, used to measure the compactness of the cluster, is the distance out to which cluster members were counted. It is defined as 1.72/z arcminutes, where z is the redshift of the cluster, which is equivalent to 1.5 h-1 Mpc, where h is the dimensionless Hubble constant in units of 100 km s-1 Mpc-1. Thus, for h= 0.75, i.e., a Hubble constant of 75 km s-1 Mpc-1, the Abell radius corresponds to a physical dimension of 2 Mpc.

Log_Redshift_Ratio
The logarithm of the ratio between the measured redshift and that which is estimated from the empirical mag_10-redshift relation for the cluster of galaxies.

Class
The HEASARC Browse object classification, based on the Abell richness class of the cluster.


Contact Person

Questions regarding the ABELLZCAT database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 1-Jun-2010