A Search for X-Ray Bright Distant Clusters of Galaxies
Abstract
We present the results of a search for X-ray luminous distant clusters of galaxies. We found extended X-ray emission characteristic of a cluster toward two of our candidate clusters of galaxies. They both have a luminosity in the ROSAT bandpass of ~10^44^ ergs s^-1^ and a redshift greater than 0.5; thus making them two of the most distant X-ray clusters ever observed. Furthermore, we show that both clusters are optically rich and have a known radio source associated with them. We compare our result with other recent searches for distant X-ray luminous clusters and present a lower limit of 1.2 x 10^-7^ Mpc^-3^ for the number density of such high-redshift clusters. This limit is consistent with the expected abundance of such clusters in a standard (b = 2) cold dark matter universe. Finally, our clusters provide important high-redshift targets for further study into the origin and evolution of massive clusters of galaxies.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1994
- DOI:
- 10.1086/174585
- arXiv:
- arXiv:astro-ph/9403033
- Bibcode:
- 1994ApJ...432..464N
- Keywords:
-
- Galactic Clusters;
- Galactic Evolution;
- X Ray Astronomy;
- X Ray Sources;
- Cosmology;
- Luminosity;
- Radio Sources (Astronomy);
- Red Shift;
- Astrophysics;
- GALAXIES: CLUSTERS OF;
- X-RAYS: GALAXIES;
- Astrophysics
- E-Print:
- 20 pages Latex file + 1 postscript figure file appended