Sunyaev-Zel'dovich effect and X-ray measurements of Abell 1995

As some of the most massive and largest structures in the universe,clusters of galaxies serve as powerful cosmological probes. The present era of X-ray astronomy provides an unprecedented view of these X-ray luminous objects, resulting in strong observational constraints on cosmological parameters. Presented in this dissertation is the X-ray and Sunyaev-Zel'dovich Effect analysis of the massive galaxy cluster Abell 1995 from which we derive constraints on the universal matter density Ω_M and the angular diameter distance to the cluster D_A. In this dissertation we present observations and analysis of (i) the X-ray imaging from the ROSAT HRI and the global spectroscopy from the SIS and GIS instruments of ASCA, (ii) the X-ray imaging and spatially resolved spectroscopy from ACIS on board the Chandra X-ray Observatory and (iii) the BIMA and OVRO 28.5 GHz interferometric imaging of the Sunyaev-Zel'dovich Effect in Abell 1995. The ACIS X-ray spectrum of this distant (z = 0.3219) cluster of galaxies shows no significant temperature or metallicity variation as a function of position in the cluster and the surface brightness profile and the spectral data show no evidence of a cooling flow in the cluster core. Using spatial and spectral parameters derived from the Chandra X-ray observations and under the assumptions that the cluster is isothermal and in hydrostatic equilibrium, we determine the total gravitational and gas mass of Abell 1995 as a function of radius. From these mass estimates a lower limit is placed on the cluster baryon fraction f_B>~0.039^+0.003_{- 0.003}h ^-3/2 within a radius of 4.0^' (0.738h ^-1 Mpc). In combination with recent baryon density constraints, the cluster baryon fraction yields an upper limit on the universal matter density parameter W_M<~0.48^+0.07_{- 0.06} h^-1/2 . Combining the Chandra X-ray imaging and spectroscopy with the 28.5 GHz interferometric Sunyaev-Zel'dovich effect measurements yields a cluster distance D_A=1844^+394+623_{-35 4- 654} Mpc (statistical followed by systematic uncertainty). Compared to the ROSAT and ASCA results, the Chandra data provide significantly smaller statistical and systematic uncertainties in the inferred parameters.