Using the photometric redshifts of galaxies from the Sloan Digital Sky Survey III (SDSS-III), we identify 132,684 clusters in the redshift range of 0.05 <= z < 0.8. Monte Carlo simulations show that the false detection rate is less than 6% for the whole sample. The completeness is more than 95% for clusters with a mass of M 200 > 1.0 × 1014 M ☉ in the redshift range of 0.05 <= z < 0.42, while clusters of z > 0.42 are less complete and have a biased smaller richness than the real one due to incompleteness of member galaxies. We compare our sample with other cluster samples, and find that more than 90% of previously known rich clusters of 0.05 <= z < 0.42 are matched with clusters in our sample. Richer clusters tend to have more luminous brightest cluster galaxies (BCGs). Correlating with X-ray and the Planck data, we show that the cluster richness is closely related to the X-ray luminosity, temperature, and Sunyaev-Zel'dovich measurements. Comparison of the BCGs with the SDSS luminous red galaxy (LRG) sample shows that 25% of LRGs are BCGs of our clusters and 36% of LRGs are cluster member galaxies. In our cluster sample, 63% of BCGs of r petro < 19.5 satisfy the SDSS LRG selection criteria.
The Astrophysical Journal Supplement Series
- Pub Date:
- April 2012
- galaxies: clusters: general;
- galaxies: distances and redshifts;
- Astrophysics - Cosmology and Extragalactic Astrophysics
- 12 pages, 20 figures, 1 table