An improved method for the identification of galaxy systems: Measuring the gravitational redshift by Dark Matter Haloes

DOMINGUEZ, M.; GARCÍA LAMBAS, DIEGO & MURIEL, HERNÁN

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2012 vol. 427 p. 6 - 10

0035-8711

We introduce a new method for the identification of galaxy systems in redshift surveys based on the halo model. This method is a modified version of the K-means identification algorithm developed by yang:04. We have calibrated and tested our algorithms using mock catalogs generated using the Millennium simulations (springel:05) and applied them to the NYU-DR7 galaxy catalog (based on the SDSS datasets). Using this local sample of groups and clusters of galaxies we have measured the effect of gravitational redshift produced by their host dark matter haloes. Our results shows radial velocity decrements consistent with general relativity predictions and previous measurements by (whh:11) in cluster of galaxies.