[ CATS home ] [ Back to CATS list ] [ ftp ]


1995AJ....109..853Ledlow+
J/AJ/109/853           VLA survey of Abell clusters. IV. (Ledlow+ 1995)
================================================================================
A 20 cm VLA survey of Abell clusters of galaxies.
IV. The radio sample and cluster properties
     Ledlow M.J., Owen F.N.
    Astron. J. 109, 853 (1995)
    =1995AJ....109..853L
================================================================================
ADC_Keywords: Clusters, galaxy ; Radio sources

Abstract:

This is the fourth in a series of papers describing an in depth study of a large statistical sample of radio galaxies in Abell clusters. This sample forms the basis of a detailed optical and radio study of the host galaxy properties, environments, and evolutionary models for radio galaxies as a class of objects. In this paper, we examine the radio detection statistics as a function of cluster morphological type, galaxy richness, and spatial location within the cluster galaxy distribution. These relationships are also parametrized as a function of radio power. The spatial distributions of the radio sources as a function of distance from the cluster center indicate that radio galaxies are preferentially located at small radii from the center of the cluster potential. This is observed as a factor of 2-3 excess over that predicted by a King-model surface-density distribution. The excess is higher in the upper radio power bin. This result is easily explained, however, from the spatial distribution of the brightest galaxies and the relationship between radio and optical luminosity. The sample is divided into richness classes 0, 1, and 2, according to Abell's criterion, and in two radio power ranges. While simple counting shows that richer clusters have more radio galaxies in both radio power bins, when the detections are scaled to the number of galaxies surveyed in each cluster, no significant correlations are found. This result implies that the number of radio galaxies detected simply scales with the number of galaxies surveyed. The higher galaxy density (and presumably higher ICM gas density) in richer clusters does not appear to affect the rate of radio source formation. The clusters are divided into Rood-Sastry and Bautz-Morgan morphological types. While it would appear that the more regular clusters have higher radio detection rates, when the classes are normalized to the number of galaxies, the radio detection rates are found to be identical regardless of cluster morphology. In conclusion, it is the optical properties of the host galaxy which most influence both the radio detection rate and the radio source properties. The cluster properties, galaxy density, and spatial location of the galaxy do not significantly affect the observed radio statistics.
File Summary:
--------------------------------------------------------------------------------
 FileName    Lrecl    Records   Explanations
--------------------------------------------------------------------------------
ReadMe          80          .   This file
table1a        137        511   Cluster radio survey (z<=0.09)
table1b         97        231   Cluster radio survey (0.09)
   6-  7  A2     ---    n_Abell    *Abell number note
  10- 15  F6.4   ---      z         []? Cluster redshift
  16- 30  A15    ---    r_z        *Redshift reference code
      31  A1     ---    n_IAU      *IAU name note
  33- 42  A10    ---      IAU       (B1950) IAU name
  44- 45  I2     h        RAh       []? Right ascension (B1950)
  47- 48  I2     min      RAm       []? Right ascension (B1950)
  50- 54  F5.2   s        RAs       []? Right ascension (B1950)
      56  A1     ---      DE-       Declination sign (B1950)
  57- 58  I2     deg      DEd       []? Declination (B1950)
  60- 61  I2     arcmin   DEm       []? Declination (B1950)
  63- 67  F5.2   arcsec   DEs       []? Declination (B1950)
  70- 75  F6.1   mJy      Flux      []? Measured flux density at 1400MHz
  77- 80  F4.2   ---      Ac       *[]? Distance from cluster center
  82- 87  F6.3   mag      2E(B-V)   []? Extinction at R band for the cluster
  89- 93  F5.2   mag      m10c     *[]? Corrected m10
  95-102  F8.4   ---      z/zest    []? Ratio log(z/z_est) based on m10c
 104-106  A3     ---    n_Status    *Status note explaining rejection
 108-129  A22    ---      Status    Status of source in statistical sample
 130-137  A8     ---      Other     Other name
--------------------------------------------------------------------------------
Note on n_Abell, n_IAU, n_Status:
   1 ID's on finder chart in O93 have labeled source A as D and source B as A.
   2 ID's on finder chart in O92 have sources A and B switched.
   3 ID's on finder chart in O93 have labeled source A as B and source B as C.
   4 ID in O93 is labeled D on finder chart.
   5 Only A is listed in O92, and is a background source.
   6 ID's on finder in O92 have labeled sources A as C, B as A, and C as B.
   7 Rejected because abs(log(z/z_est))>0.24.
   8 Rejected because source is greater than 0.3 A_c from cluster center.
   9 Rejected because galactic absorption is greater than 0.1 magnitudes.
  10 Cluster was rejected because redshift is too low to have surveyed
        0.5 A_c field.
  11 Measured velocity was too different from mean cluster velocity
Note on r_z : Number in parentheses following reference code is the number
  of galaxies used to compute the redshift.  Reference codes are:
  (ACO) Abell G.O. et al., 1989, ApJS, 70, 1  
  (H) Huchra J.P. 1989, private communication
  (L) Lebedev V.S. and Lebedeva I.A. (1986ATsir1469....4L)
  (OH) Oegerle W. and Hill J. M. (1992AJ....104.2078O)
  (O92) Owen F.N. et al. (1992ApJS...80..501O)
  (O93) Owen F.N. et al. (1993ApJS...87..135O)
  (P) Postman M. et al. 
  (SGH) Schneider D.P. et al. (1983ApJ...264..337S)
  (S) Struble M.F. and Rood H.J. 
  In on case, A2149, this column contains a second redshift
Note on Ac: The distance of the galaxy from the cluster center positions of
  Abell [1958ApJS....3..211A]  expressed in units of a fraction of an
  Abell radius.
Note on m10c: The magnitude of the tenth brightest cluster galaxy corrected for
  the Scott effect and K-dimming
--------------------------------------------------------------------------------

Byte-by-byte Description of file: table1b
--------------------------------------------------------------------------------
   Bytes Format  Units    Label      Explanations
--------------------------------------------------------------------------------
   1-  4  A4     ---      Abell      Abell cluster number
       6  A1     ---    n_Abell     *Abell number note
   8- 19  A12    ---      Redshift  *Cluster redshift and reference code
  21- 30  A10    ---      IAU        (B1950) IAU name
  32- 33  I2     h        RAh        []? Right ascension (B1950)
  35- 36  I2     min      RAm        []? Right ascension (B1950)
  38- 42  F5.2   s        RAs        []? Right ascension (B1950)
      44  A1     ---      DE-        Declination sign (B1950)
  45- 46  I2     deg      DEd        []? Declination sign (B1950)
  48- 49  I2     arcmin   DEm        []? Declination sign (B1950)
  51- 54  F4.1   arcsec   DEs        []? Declination sign (B1950)
  56- 60  I5     mJy      Flux       []? Measured flux density at 1400MHz
  62- 66  F5.2   ---      Ac        *[]? Distance from cluster center
  68- 72  F5.2   mag      2E(B-V)    []? Extinction at R band for the cluster
  74- 76  A3     ---    n_Status    *Status note explaining rejection
  78- 97  A20    ---      Status     Status of Source in statistical sample
--------------------------------------------------------------------------------
Note on n_Abell, n_Status:
  1 Cluster has High R-Extinction, but kept because source is FR2
  2 Cluster found to have z<0.09. Left in sample, but not included
      analysis
  3 Radio flux slightly below 200 mJy cutoff, but left in sample
  4 ID's on finder chart in O92 have sources A as B and B listed as C
  5 Rejected because source is >0.5A_c from cluster center
  6 Rejected because galactic absorption is >0.1 magnitudes
Note on Redshift:
  Number in parentheses following reference code is the number of
  galaxies used to compute the redshift. Reference codes are:
  (H) Huchra, J.P. 1989, private communication
  (L) Lebedev V.S. and Lebedeva I.A. (1986ATsir1469....4L)
  (O92) Owen F.N. et al. (1992ApJS...80..501O)
  (OLK) Owen F.N. et al. (1995AJ....109...14O)
  (OWT) Owen F.N. et al. (1988AJ.....95....1O)
  (P) Postman M.et al. 
  (S) Struble M.F. and Rood H.J. 
Note on Ac: The distance of the galaxy from the cluster center positions of
  Abell [1958, ApJS, 3, 211]  expressed in units of a fraction of an
  Abell radius.
--------------------------------------------------------------------------------

For correspondence or questions, contact :
    Dr. Michael Ledlow
    E-mail: 
    Phone : (505)646-3000
    Address : New Mexico State University
              Department of Astronomy
              Box 30001/Dept. 4500
              Las Cruces, NM  88003-0001


Origin: AAS CD-ROM series, Volume 4, 1995         Lee Brotzman [ADS] 02-May-1995

Modifications made at CDS:
  In table1a the formats of '2E(B-V)' and 'z/zest' were changed to accommodate
  3 and 4 decimals; column 'Flux' was also changed from I7 to F6.1

References:
   Zhao et al., Paper I, 1989AJ.....98...64Z
   Owen et al., Paper II, 1992ApJS...80..501O
   Owen et al., Paper III, 1993ApJS...87..135O
   Ledlow & owen, Paper IV, 1995AJ....110.1959
================================================================================
(End)                                                         [CDS]  12-Jul-1995