Properties of bright galaxies in galaxy clusters and their dependency on the environment

In this thesis, red-sequence galaxies determined from the color-magnitude diagrams of galaxy clusters were investigated both in the cluster centers and in the outer parts. It has been observed that the slope of the red-sequence in clusters determined by two different cluster detection algorithms (WaZP and CAMIRA) and two different surveys (CFHTLS and Subaru HSC-SSP) is not a function of redshift. In addition, it has been determined that the slope is very similar in rich and poor clusters suggesting that the slope is independent of the environment. The change of the faint/luminous galaxy number ratios in the red-sequence was investigated as a function of both the richness and the redshift. It has been shown that, regardless of the position of galaxies in the cluster, the ratio of faint/luminous galaxies at low redshifts is higher than the ratio at high redshifts. Finally, comparing structural parameters of the three brightest galaxies in clusters suggests that BCGs constitute an unique galaxy population in terms of their effective radius and Sérsic index.