Measuring the redshift dependence of the CMB monopole temperature with PLANCK data

TL;DR

This paper demonstrates that PLANCK data can precisely measure the redshift dependence of the CMB temperature, improving constraints on deviations from adiabatic evolution by analyzing Sunyaev-Zeldovich effects in galaxy clusters.

Contribution

The study introduces a novel analysis of PLANCK data using two statistical estimators to constrain the CMB temperature's redshift evolution with improved accuracy over previous methods.

Findings

Achieved a constraint of σ_α=0.011 in the most optimal case.

Improved measurement accuracy by a factor of 2-3 over quasar-based methods.

Enhanced constraints by a factor of 6-20 compared to earlier cluster sample analyses.

Abstract

We study the power of PLANCK data to constrain deviations of the Cosmic Microwave Background black body temperature from adiabatic evolution using the thermal Sunyaev-Zeldovich anisotropy induced by clusters of galaxies. We consider two types of data sets: the cosmological signal is removed in the Time Ordered Information or is removed from the final maps; and two different statistical estimators, based on the ratio of temperature anisotropies at two different frequencies and on a fit to the spectral variation of the cluster signal with frequency. To test for systematics, we construct a template from clusters drawn from a hydro-simulation included in the pre-launch Planck Sky Model. We demonstrate that, using a proprietary catalog of X-ray selected clusters with measured redshifts, electron densities and X-ray temperatures, we can constrain deviations of adiabatic evolution, measured by the parameter $\alpha$ in the redshift scaling $T(z)=T_0(1+z)^{1-\alpha}$, with an accuracy of $\sigma_\alpha=0.011$ in the most optimal case and with $\sigma_\alpha=0.016$ for a less optimal case. These results represent a factor 2-3 improvement over similar measurements carried out using quasar spectral lines and a factor 6-20 with respect to earlier results using smaller cluster samples.