Back to Volume
Paper: Evolution of the Cluster Abundance from the ROSAT Deep Cluster Survey
Volume: 176, Observational Cosmology: The Development of Galaxy Systems
Page: 40
Authors: Borgani, Stefano; Rosati, Piero; Tozzi, Paolo; Norman, Colin
Abstract: We use results from the Rosat Deep Cluster Survey (RDCS, Rosati et al. 1998) to characterize the evolution of the cluster abundance out to redshift z≈ 0.8. Based on the Press--Schechter approach to follow the evolution of the mass--function and on an empirical prescription to convert masses into observed X--ray cluster fluxes, we obtain constraints on cosmological models. We apply a maximum--likelihood approach to the RDCS redshift-- and luminosity--distribution. Although the resulting constraints on Ω_0 are sensitive to the assumed X--ray luminosity--temperature relation, we find that a low--density Universe with Ω_0≈ 0.3--0.5 is in general to be preferred with respect to the Ω_0 = 1 case. A critical--density Universe would require a rather strong positive evolution of the L_X--T_X relation, which seems to be in contrast with current observations.
Back to Volume