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1996AuJPh..49..977Slee,Roy & Andernach

A VLA Survey of Rich Clusters of Galaxies III. The weaker sources

Abstract

We present radio and optical parameters for 737 weak sources in 60 Abell cluster fields observed with the Very Large Array (VLA) using scaled arrays at 1.5 and 4.9 GHz. The measurements extend to a lower 1.5 GHz limit of 1.0 mJy and comprise a complete sample with 1.5-GHz flux density 2.5 S1.5 < 20 mJy The combined sky area within the half-power circle on the maps is 3.5 x 10-3 sr, and the cluster fields are distributed over 24 h of right ascension and between declinations +35deg and -30deg. Contour maps of the extended sources at 1.5 GHz are presented and source parameters such as position, angular size and spectral index are tabulated. We also derive the emitted power and linear size for those sources with published redshifts. We try to identify the radio sources with optical images on the Palomar and SERC survey plates and give their accurate optical positions, morphologies and apparent magnitudes.
J/AuJPh/47/145        VLA Survey of Rich Clusters of Galaxies II  (Slee+, 1994)
J/AuJPh/49/977        VLA Survey of Rich Clusters of Galaxies III (Slee+, 1996)
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A  VLA Survey of Rich Clusters of Galaxies II. The Stronger Sources: Maps,
           Polarisations and Identifications
     Slee O.B., Roy A., Savage A.

A  VLA Survey of Rich Clusters of Galaxies III. The Weaker Sources: Maps
           and Identifications
     Slee O.B., Roy A., Andernach H.

    
    
    =1994AuJPh..47..145S      (SIMBAD/NED BibCode)
    =1996AuJPh..49..977S      (SIMBAD/NED BibCode)
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Keywords: galaxies: clusters of - radio continuum: galaxies; surveys - 
          radio sources: optical identification 

Description:
    We observed 60 fields towards 57 Abell and one Zwicky cluster of galaxies 
    using the Very Large Array (VLA) with scaled arrays at 1.5 and 4.9 GHz. 
    The source catalogue contains radio and optical parameters for 994 sources 
    up to a lower flux limit of 1.0 mJy at 1.5 GHz and comprises a complete sample 
    above 2.5 mJy. The combined sky area within the half-power circle on the maps 
    is 3.5 10^-3 sr, and the cluster fields are distributed between +35 deg
    and -30 deg declination. The source catalogue list positions, angular
    size, spectral index and optical identification, magnitude and morphology,
    if available.

See also:
    1989AuJPh..42..633Slee+; Catalogue of 937 Radio Sources towards
          58 Galaxy Clusters  (= paper I)

File Summary:
--------------------------------------------------------------------------------
  FileName      Lrecl  Records   Explanations
--------------------------------------------------------------------------------
ReadMe             80        .   This file
table1            105       60   Properties of the observed clusters
catalog           109     1037   Radio and optical parameters of sources
--------------------------------------------------------------------------------
Note on catalog:
   The source catalogues from papers II and III were merged, as well as
   the radio and the optical information joined into a single table. For
   each source only the most likely optical candidates (if any) were
   retained. This merged table replaces the one published in paper I
   =1989AuJPh..42..633Slee+ ). Tables on structural details of multiple 
   sources as published in papers II and III are available upon request 
   to the authors.

Byte-by-byte Description of file: table1
--------------------------------------------------------------------------------
   Bytes Format  Units   Label    Explanations
--------------------------------------------------------------------------------
   1-  7  A7     ---       Field     Name of observed field  (1)
       9  A1     ---       fnote     Note on the field  (2)
  11- 12  I2     h         RAh       Right ascension of cluster centre(1950) (3)
  14- 17  F4.1   min       RAm       Right ascension of cluster centre(1950) (3)
      19  A1     ---       DE-       Declination sign
  20- 21  I2     deg       DEd       Declination of cluster centre (1950)  (3)
  23- 24  I2     arcmin    DEm       Declination of cluster centre (1950)  (3)
  27- 30  F4.1   arcmin    ROoff     Offset of radio field centre from optical
                                      cluster centre
  33- 36  F4.2   ---       offRcl    Offset of radio field centre from optical
                                      cluster centre in units of cluster radii
  38- 43  F4.1   deg       ROPang    Position angle of vector from optical 
                                     cluster centre to radio field centre
                                     (positive from N through E)
  46- 48  I3     uJy/beam  rms_1.5   rms noise of radio map at 1.5 GHz
  50- 52  I3     uJy/beam  rms_4.9   rms noise of radio map at 4.9 GHz
      55  I1     ---       Rclass    Abell richness class of cluster
      57  I1     ---       Dclass    Abell distance class of cluster
  59- 62  F4.1   mag       m10R      red magnitude of 10th brightest galaxy
  64- 69  A6     ---       BMclass   Bautz-Morgan (BM) class of cluster
      70  A1     ---       u_BM      [ :] uncertainty flag on BM class 
  72- 73  A2     arcmin    R_clu     angular cluster radius  (4) 
  76- 79  F4.2   Mpc       Rclin     linear cluster radius (H0=75km/s/Mpc)
  82- 87  F6.4   ---       zclu      cluster redshift  
      90  A1     ---       zref      reference for cluster redshift  (5)
  93- 97  F5.2   erg/s     lgxein    log of EINSTEIN X-ray luminosity (6)
      99  A1     ---       lxflag    [ R] R= ROSAT measurement converted to
                                      EINSTEIN luminosity scale (see paper)
 101- 105 F5.2   erg/s     lgxros    log of ROSAT X-ray luminosity from 
                                      Ebeling 1993 (PhD MPE Garching)
--------------------------------------------------------------------------------
Note (1):
   'A' stands for 'Abell cluster' and Z1518.8 stands for the Zwicky cluster
   Zw1518.8+0747. Two clusters (A 85 and A154) were observed with two
   different field centers.

Note (2):
  *= The RA is from Abell et al. (1989). The incorrect RA of Abell (1958)
     was used for the radio field centre - hence the large offset.
  #= Data from Abell et al. (1989) =1989ApJS...70....1A
  = Data from "Catalogue of Galaxies and of Clusters of Galaxies" 
     (Zwicky et al. 1961) and Slee & Quinn (1979) =1979PASAu...3..332S

Note (3):
   The centroid position (B1950) of the optical cluster, mainly from 
   Abell (1958) (=1958ApJS....3..211A), but data for three clusters come 
   from Abell et al. (1989) (=1989ApJS...70....1A) and Zwicky et al. (1961).

Note (4):
   Rclu is the cluster radius from the Palomar Sky Survey 
   (Struble & Rood 1987 =1987ApJS...63..555S) except that the Abell 
   radius (approximately 1.72/z arcmin) is quoted for A3528, Zw1518.8, A4038.

Note (5):
   Redshift references :
   1  Struble & Rood            =1991ApJS...77..363S
   2  From the m10-z relation   =1994AuJPh..47..145S  
        (Slee, Roy & Savage       SRS94, Paper II)
   3  Melnick & Quintana        =1981A&AS...44...87M
   4  Abell et al.              =1989ApJS...70....1A
   5  Beers et al.              =1991AJ....102.1581B
   6  Slee & Reynolds           =1984PASAu...5..516S
   7  Reynolds 1986             =1986USydn.T00J....R
   8  Postman et al.            =1992ApJ...384..404P

Note (6):
   The EINSTEIN X-ray luminosity in the energy range 0.5-4.5 keV and out to a 
   radius of 1Mpc from the cluster centre. The data (scaled to H_o=75 km/s/Mpc) 
   are from Jones & Forman (1995, unpubl.).

Byte-by-byte Description of file: tab25
--------------------------------------------------------------------------------
   Bytes Format  Units   Label    Explanations
--------------------------------------------------------------------------------
   1- 14  A14    ---       Name      Name of cluster (A=Abell, Z=Zwicky)  (1)
      16  A1     ---       multID    [ #] # denotes one of several optical 
                                      identifications for the same source
      17  A1     ---       IDnum     Sequence number of optical ID
  20- 21  I2     h         RAh       Right ascension of radio centroid (1950)
  22- 23  I2     min       RAm       Right ascension of radio centroid (1950)
  24- 28  F5.2   s         RAs       Right ascension of radio centroid (1950)
      30  A1     ---       DE-       Declination sign
  31- 32  I2     deg       DEd       Declination of radio centroid (1950)
  33- 34  I2     arcmin    DEm       Declination of radio centroid (1950)
  35- 38  F4.1   arcsec    DEs       Declination of radio centroid (1950)
  40- 41  A2     ---       paper     number of paper in which the source was
                                       published ('2 '=II; ' 3'=III; '23'=both)
  43- 46  F4.2   ---       pdist     projected distance of radio source from
                                      cluster center in units of Rc (see table1)
  48- 53  F6.1   mJy       F1.5      integrated 1.5GHz flux density
  55- 59  F5.1   mJy       F4.9      integrated 4.9GHz flux density
  61- 64  F4.1   ---       alpha     spectral index between 1.5 and 4.9 GHz (2)
  67- 69  I3     arcsec    majax     size of source major axis (deconvolved) (3) 
  71- 72  I2     arcsec    minax     size of source minor axis (deconvolved) (3)
  74- 76  I3     deg       PosAng    position angle of major axis (N thru E)
  78- 81  A4     ---       omorph    optical morphology of most likely ID (4)
      82  A1     ---       Rmag_flg  [ >] upper limit flag for Rmag (4)
  83- 86  F4.1   mag       Rmag      red magnitude from POSS prints (4)
  88- 91  F4.1   mag       Jmag      blue (B_j) magnitude from SERC plates (4)
  94- 95  I2     arcsec    ORoff     Positional offset of opt. ID with respect to
                                     radio centroid
  97-100  I4     deg       offPA     Position angle of vector pointing from radio
                                     centroid to opt. ID (positive N through E)
 103-108  F6.4   ---       z         heliocentric redshift of opt. ID, if 
                                      available (references see paper)
--------------------------------------------------------------------------------
Note (1):
  The source name is composed of the name of cluster (A=Abell, Z=Zwicky, in
  A5 format), an underscore symbol, the source running number within the
  observed field (optionally appended by a roman numeral), and an optional list 
  of subcomponents (a, ab, abc...) which indicate the presence of more detailed 
  structural data in tables 3 and 4 of both papers II and III. Note that Z1518 
  stands for the Zwicky cluster Zw1518.8+0747. The source running numbers are 
  those of paper I. However, a few of the weak sources listed in Paper I (e.g.
  A0133_10) were omitted because subsequent analysis showed that they were 
  probably spurious. To avoid later confusion, the additional sources are 
  inserted in the Table at the correct right ascension but are given an 
  extra lower case Roman numeral.  For example, the source A0013_13 in table 2 
  of paper I is now A0013_13i, while the source A0013_13ii_ab of slightly 
  later RA (as well as two components a and b) has been inserted in the 
  present source list.  In one case two sources (A1913_6 and A1913_8) were 
  merged to a single source (A1913_6,8).


Note (2):
  The spectrum is defined as F(freq)~freq^alpha. The spectral index is
  between 1.5 and 4.9 GHz. When no 4.9 GHz flux is listed in the table,
  the spectral index is between 1.5 GHz and another frequency taken from
  references quoted in the printed version of the papers.

Note (3):
  An elliptical Gaussian was fitted to the source. The quoted values are
  the full widths at half power, deconvolved with the antenna beam,
  and corrected for bandwidth smearing.

Note (4):
  The optical identifications were classified into the following categories:
  E    = elliptical galaxy (ie. visibly extended, surrounded by a diffuse
         structureless halo with axial ratio <~2
  D    = elliptical galaxy several times larger than all neighbouring galaxies
         if well away from cluster centre
  cD   = same as D if close to the cluster centre
  DB   = two barely resolved elliptical galaxies (dumb-bell galaxy)
  G    = galaxy (diffuse image too faint to assign a galaxy class)
  Q    = quasar known from literature
  S0   = as 'E' above but with an axial ratio >~2 
  Sp   = spiral galaxy (galaxy with considerable structure in the halo)
  St   = image with a sharp circular boundary and sometimes showing
         diffraction spikes

  The symbol 'x2' is appended to double objects, for which the summed magnitude
  is quoted in the subsequent colums. Very faint images are difficult 
  to assign to the G or St categories and often the choice is rather arbitrary.
  If an image was detected on the B_j plates, but not on the red POSS prints
  a conservative upper limit of ">19.5" is quoted for the red magnitude.
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(End)                               Heinz Andernach [IUE Vilspa]    23-Oct-1996