NED Abstract 
Copyright by American Astronomical Society.
Reproduced by permission

1996AJ....111..615P

       THE PALOMAR DISTANT CLUSTER SURVEY. I. THE CLUSTER CATALOG

                              MARC POSTMAN
  Space Telescope Science Institute,2 3700 San Martin Drive, Baltimore, 
                             Maryland 21218
                   Electronic mall: postman@stsci.edu

                     LORI M. LUBIN AND JAMES E. GUNN
      Princeton University Observatory, Princeton, New Jersey 08544
         Electronic mall: lml@ociw.edu, jeg@astro.princeton.edu

                                J. B. OKE
   Palomar Observatory, California Institute of Technology, Pasadena, 
 California 91125, and Dominion Astrophysical Observatory, Victoria, BC 
                             V8X 4M6, Canada
                 Electronic mall: jbo@cygnus.dao.nrc.ca

                             JOHN G. HOESSEL
  Washburn Observatory, University of Wisconsin-Madison, 475 N. Charter 
                      St., Madison, Wisconsin 53706
              Electronic mail: hoessel@uwtpe.astro.wisc.edu

                           DONALD P. SCHNEIDER
    Department of Astronomy and Astrophysics, The Pennsylvania State 
  University, 525 Davey Lab, University Park, Pennsylvania 16802, and 
Institute for Advanced Study, School of Natural Sciences, Princeton, New 
                              Jersey 08540
                Electronic mail: dps@miffy.astro.psu.edu

                         JENNNER A. CHRISTENSEN
  Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, 
                             Maryland 21218
                   Electronic mall: christen@stsci.edu
             Received 1995 July 26; revised 1995 November 6

                                ABSTRACT
We present an optical/near-IR selected catalog of 79 clusters distributed 
over an area of 5.1^deg^ sq. The catalog was constructed from images 
obtained with the 4-Shooter CCD mosaic camera on the Hale 5 m telescope 
operating in "scan" mode. The survey, hereafter known as the Palomar 
distant cluster survey (PDCS), was conducted in two broadband filters 
that closely resemble V and I. The 4 {sigma} limiting magnitudes for our 
300 s exposures are ~23.8(V) and 22.5 (I). A matched filter algorithm was 
developed and employed to identify the cluster candidates by using 
positional and photometric data simultaneously. The clusters cover the 
range 0.2 <~ z <~ 1.2, based on the redshift estimates derived in the 
cluster detection procedure. An accurate selection function is generated 
from extensive simulations. We find that the cumulative surface density 
of clusters with richness class R => 1 is about a factor of 5 higher than 
the extrapolated density of R => 1 Abell clusters. The PDCS results are 
consistent with a constant comoving density of clusters to z <~ 0.6, 
albeit at the above high density level. Constraints on cluster abundances 
at z > 0.6 will be possible with the acquisition of spectroscopic 
redshifts for a large subset of these cluster candidates. We also present 
a supplemental catalog of 28 clusters that do not satisfy all our 
selection criteria but which include some of the most distant systems 
detected in the survey. Finding charts for all 107 cluster candidates are 
provided.