Probing our universe with sunyaev - Zel'dovich effect

Abstract

In this thesis, we look at both thermal Sunyaev-Zel’dovich (SZ) distortion as well as kinematic Sunyaev-Zel’dovich distortion of the Cosmic Microwave Background due to several possible astrophysical sources, namely, clusters of galaxies, galactic winds at high redshifts, and radio galaxies.

We find that the presence of cooling flows can lead to an over-estimation of the value of the Hubble constant by ~10% using SZ and X-ray observations of clusters of galaxies. Based on a comparison of the rms temperature anisotropy, obtained from simulated maps of SZ distortions of the CMB due to galaxy clusters, with Australia Telescope Compact Array limits on arc-minute scale anisotropies, we have constrained cosmological models. We have further used the power spectrum of the SZ effect from galaxy clusters as an additional cosmological probe and also as a probe of cluster-specific properties, like the cluster gas mass fraction.

We have calculated the SZ distortion (the mean y-distortion and the angular power spectrum) by galactic winds originating at high redshifts and found the kinetic SZ effect to be more important than the thermal SZ effect. The total power spectrum of SZ distortion from galactic winds is found to dominate over that from clusters of galaxies at 217 GHz; the frequency at which the thermal SZ effect is zero. A possible detection of the power spectrum of SZ distortion due to winds has been proposed as a tool to yield information on bias at high redshifts.

Finally, we have looked at the SZ effect by radio galaxies and found the resultant y ~ 6 × 10?? from distortion by the non-thermal plasma inside the cocoons. We also estimated the thermal SZ distortion from the gas heated by the work done by the cocoons to be ~ 5 × 10??. For cocoons inside clusters, we have found the mean y-distortion to be of the order ~ 5 × 10??