Estimating the Sunyaev - Zel'dovich signal from quasar hosts using a Halo Occupation Distribution based approach

TL;DR

This paper estimates the Sunyaev-Zeldovich signal from quasar host galaxies using a Halo Occupation Distribution approach, finding that the observed signals can be explained without invoking quasar feedback.

Contribution

It introduces a novel method using measured Halo Occupation Distribution properties to estimate SZ signals from quasar hosts, challenging previous interpretations of feedback effects.

Findings

SZ signal decreases with redshift, consistent with observations.

Model explains Ruan et al.'s detection without feedback.

Halo signal alone can account for observed SZ effects.

Abstract

The Sunyaev-Zeldovich (SZ) effect is a spectral distortion in the Cosmic Microwave Background (CMB), caused due to up-scattering of CMB photons by high energy electron distributions. The largest SZ distortion in the CMB is caused by the hot electrons present in the intra-cluster medium (ICM). However, several other small scale astrophysical processes can also contribute to the SZ distortion in the CMB. Analytic studies have shown that the interstellar (ISM) electron gas of the host galaxy heated by quasar feedback can also cause substantial SZ effect. For successful detection of the quasar feedback signal, the SZ signal from the virialized gas in the host halos of quasars needs to be properly quantified. In this dissertation work, I have estimated the SZ signal from quasar hosts using analytic models of the virialized gas in the ICM/ISM. As a new extension to existing work I have used the measured Halo Occupation Distribution properties of quasar hosts. The results show that the average SZ signal from quasar hosts decreases with redshift. This result is consist what what has been observed by the Planck team. I have compared by calculations with the experimental results of Ruan et al. (2015). While Ruan et al. (2015) claim their detection to be from quasar feedback, I find that within the errors of my model, their detection can be explained with halo signal alone, without introducing feedback.