NED Abstract 
Copyright by American Astronomical Society.
Reproduced by permission

2000ApJS..126..209R

               The Bright SHARC Survey: The Cluster Catalog

                       A. K. Romer and R. C. Nichol
  Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue,
            Pittsburgh, PA 15213; [email protected], [email protected]

                               B. P. Holden
   Department of Astronomy and Astrophysics, University of Chicago, 5640
     South Ellis Avenue, Chicago, IL 60637; [email protected]

                       M. P. Ulmer and R. A. Pildis
 Department of Physics and Astronomy, Northwestern University, 2131 North
       Sheridan Road, Evanston, IL 60207; [email protected]

                              A. J. Merrelli
  Department of Physics, Carnegie Mellon University, 5000. Forbes Avenue,
               Pittsburgh, PA 15213; [email protected]

                                 C. Adami
 Department of Physics and Astronomy, Northwestern University, 2131 North
    Sheridan Road, Evanston, IL 60207; [email protected]; and
  Laboratoire d Astronomie Spatiale, Traverse du Siphon, 13012 Marseille,
                                  France

                      D. J. Burke  and C. A. Collins
 Astrophysics Research Institute, Liverpool John Moores University, Twelve
Quays House, Egerton Wharf, Birkenhead, L41 1LD, UK; [email protected],
                           [email protected]

                              A. J. Metevier
   UCO/Lick Observatory, University of California, Santa Cruz, CA 95064;
                             [email protected]

                                R. G. Kron
   Department of Astronomy and Astrophysics, University of Chicago, 5640
      South Ellis Avenue, Chicago, IL 60637; [email protected]

                                    and
                                K. Commons
 Department of Physics and Astronomy, Northwestern University, 2131 North
      Sheridan Road, Evanston, IL 60207; [email protected]
              Received 1999 April 12; accepted 1999 August 23

                                 ABSTRACT
   We present the Bright SHARC (Serendipitous High-Redshift Archival ROSAT 
Cluster) Survey, which is an objective search for serendipitously detected 
extended X-ray sources in 460 deep ROSAT PSPC pointings. The Bright SHARC 
Survey covers an area of 178.6 deg^2^ and has yielded 374 extended sources.  
We discuss the X-ray data reduction, the candidate selection and present 
results from our on-going optical follow-up campaign. The optical follow-up 
concentrates on the brightest 94 of the 374 extended sources and is now 97% 
complete. We have identified 37 clusters of galaxies, for which we present 
redshifts and luminosities. The clusters span a redshift range of 0.0696 < 
z < 0.83 and a luminosity range of 0.065 < L_X_ < 8.3 x 10^44^ ergs s^-1^ 
[0.5 -2.0 keV] (assuming H_0_ = 50 km s^-1^ Mpc^-1^ and q_0_ = 0.5). Twelve 
of the clusters have redshifts greater than z = 0.3, eight of which are at 
luminosities brighter than L_X_ = 3 x 10^44^ ergs s^-1^. Seventeen of the 
37 optically confirmed Bright SHARC clusters have not been listed in any 
previously published catalog.  We also report the discovery of three 
candidate "fossil groups" of the kind proposed by Ponman et al.

Subject headings: catalogs-galaxies: clusters:  general-galaxies: distances 
and redshifts-surveys-X-rays: galaxies