# Constraints on the redshift evolution of astrophysical feedback with Sunyaev-Zeldovich effect cross-correlations

## TL;DR

This paper uses galaxy and Compton-$y$ map cross-correlations from DES and Planck data to measure the evolution of gas pressure in dark matter halos, constraining astrophysical feedback models across redshifts.

## Contribution

It provides the first joint analysis of galaxy-$y$ cross-correlations and clustering to constrain halo gas pressure evolution from $z=0.15$ to $0.75$, comparing results with hydrodynamical simulations.

## Key findings

- Detected galaxy-$y$ cross-correlation at ~12σ significance across multiple redshift bins.
- Constrained the redshift evolution of halo gas pressure and feedback effects.
- Compared measurements with simulations to estimate thermal energy in halo gas.

## Abstract

An understanding of astrophysical feedback is important for constraining models of galaxy formation and for extracting cosmological information from current and future weak lensing surveys. The thermal Sunyaev-Zel'dovich effect, quantified via the Compton-$y$ parameter, is a powerful tool for studying feedback, because it directly probes the pressure of the hot, ionized gas residing in dark matter halos. Cross-correlations between galaxies and maps of Compton-$y$ obtained from cosmic microwave background surveys are sensitive to the redshift evolution of the gas pressure, and its dependence on halo mass. In this work, we use galaxies identified in year one data from the Dark Energy Survey and Compton-$y$ maps constructed from Planck observations. We find highly significant (roughly $12\sigma$) detections of galaxy-$y$ cross-correlation in multiple redshift bins. By jointly fitting these measurements as well as measurements of galaxy clustering, we constrain the halo bias-weighted, gas pressure of the Universe as a function of redshift between $0.15 \lesssim z \lesssim 0.75$. We compare these measurements to predictions from hydrodynamical simulations, allowing us to constrain the amount of thermal energy in the halo gas relative to that resulting from gravitational collapse.