Investigation of properties of galaxy clusters in the Hercules supercluster region

摘要

We investigated the properties of galaxy clusters in the region of the Hercules supercluster using observational data from the SDSS and 2MASS catalogs and the NED. We have selected 13 galaxy clusters with a total dynamical mass of 4. 82 × 10~15M_⊙ in a 100 × 45 Mpc supercluster region in the plane of the sky (0. 030 < z < 0. 041). In addition, our sample includes eight clusters from the immediate neighborhoods of the superclusters and ten field clusters at the same z. The derived properties of the rich Hercules supercluster are shown in comparison with the data for the poor Leo supercluster. The main parameters of the virialized galaxy cluster regions in the near infrared (K_s) for the Hercules supercluster differ from those for the Leo supercluster: the number of galaxies and the total luminosity (to a limiting magnitude of -21· ~m5) increase with cluster mass (L_(K,200) ∝ M_200 0. 91±0. 07 and N_200 ∝ M_200 0. 94±0. 07), but the dependences are steeper by 0. 28 and 0. 22. In the virialized cluster regions, the fraction of early-type galaxies selected by the bulge contribution, concentration index, and u t= r color is, on average, 66% (60% in Leo, 70% in the field) among the galaxies brighter than -23· ~m3 and 54% (51% in Leo, 61% in the field) among the galaxies brighter than -22· ~m3. The fraction of early-type galaxies in the superclusters does not change with galaxy cluster mass and luminosity. The composite luminosity function of the rich Hercules supercluster is described by a Schechter function and does not differ from the luminosity function of the poor Leo supercluster for the luminosity interval [-26~m, -21· ~m5] but differs from the field luminosity function at the same z determined from ten galaxy clusters.