Analysis of the properties of galaxy clusters in the Leo supercluster region

摘要

We analyze the properties of galaxy clusters in the region of the Leo supercluster using observational data from the SDSS and 2MASS catalogs. We have selected 14 galaxy clusters with a total dynamical mass of 1.77 × 10~(15)M_⊙ in the supercluster region 130 by 60 Mpc in the plane of the sky (z?0.037). The composite luminosity function of the supercluster is described by a Schechter function with parameters that, within the error limits, correspond to field galaxies and does not differ from the luminosity function of the richer Ursa Major (UMa) supercluster for the same luminosity range (the bright end). The luminosity functions of early-type and late-type galaxies in Leo at the faint end are characterized by a sharp decrease (α = -0.60±0. 08) and a steep increase (α = -1.44± 0.10) in the number of galaxies, respectively. In the virialized cluster regions, the fraction of early-type galaxies selected by the u-r color, bulge contribution, and concentration index among the galaxies brighter than M_K~*+ 1 is, on average, 62%. This fraction is smaller than that in the UMa supercluster at a 2-3σ level. The near-infrared luminosities of galaxy clusters down to a fixed absolute magnitude correlate with their masses almost in the same way as for other samples of galaxy clusters (L_(200,K) ~∝ M_(200)~(0. 63±0. 11))).