The non-thermal secondary CMB anisotropies from a cosmic distribution of radio galaxy lobes

TL;DR

This paper models the secondary CMB anisotropies caused by radio galaxy lobes, predicting their power spectrum and non-thermal y-distortion, and discusses their detectability with future experiments like PIXIE and CMB-HD.

Contribution

It provides the first computation of the CMB fluctuation power spectrum from a cosmological distribution of evolving radio galaxy lobes, including non-thermal electron effects.

Findings

Non-thermal y-distortion  less than 10^{-5} and within COBE limits.

Non-thermal SZ power spectrum peaks at   3000 with  1% of thermal SZ.

Future experiments can detect non-thermal signals and constrain black hole-halo relations.

Abstract

Current and upcoming high angular resolution and multi-frequency experiments are well poised to explore the rich landscape of secondary CMB anisotropies. In this context, we compute for the first time, the power spectrum of CMB fluctuations from a cosmological distribution of evolving lobes of giant radio galaxies. We, also, explicitly take into account the non-thermal electron distribution, which has important implications for the inference of the CMB angular power spectrum. We calculate the mean global non-thermal y-distortion, \ynt. For observationally reasonable distribution of the jet luminosities in the range of $10^{45}-10^{47}$ ergs$^{-1}$, we find \ynt to be less than $10^{-5}$, and hence not violating the COBE limit as previously claimed. Using the unique spectral dependence of the non-thermal SZ, we show that a detection of \ynt can be within reach at the level of $\gtrsim 5\sigma$ from a future PIXIE-like experiment provided we understand the foregrounds precisely. The total non-thermal SZ power spectrum, $C^{NT}_\ell$, from the radio lobes peaks at $\ell \sim 3000$ with an amplitude $\sim 1\%$ of thermal SZ power spectrum from galaxy clusters. A a detection of the $C^{NT}_\ell$, with a PIXIE-like sensitivity experiment, can lead to $\sim 5\sigma$ constraint on the mass dependence of the jet luminosity with the constraint becoming, at least, ten times better for the proposed more ambitious CMB-HD survey. This will, further, lead to the tightest constrain on the central black hole mass -to- host halo mass scaling relations.