The Thermal Sunyaev-Zel'dovich Effect from Massive, Quiescent 0.5 $\leq$ z $\leq$ 1.5 Galaxies

TL;DR

This study measures the thermal Sunyaev-Zel'dovich effect around massive, quiescent galaxies at redshifts 0.5 to 1.5 using combined SPT and Planck data, revealing insights into the circumgalactic medium's energy content and dust properties.

Contribution

It provides the first detailed measurement of the tSZ effect in high-redshift quiescent galaxies, including a model for the energy-mass relation and dust contamination correction.

Findings

Detection of tSZ signal up to 5.6σ per stellar mass bin

Measurement of the energy-mass relation with a power-law index of ~3.77

Radial profile consistent with lower-redshift observations

Abstract

We use combined South Pole Telescope (SPT)+Planck temperature maps to analyze the circumgalactic medium (CGM) encompassing 138,235 massive, quiescent 0.5 $\leq$ z $\leq$ 1.5 galaxies selected from data from the Dark Energy Survey (DES) and Wide-Field Infrared Survey Explorer (WISE). Images centered on these galaxies were cut from the 1.85 arcmin resolution maps with frequency bands at 95, 150, and 220 GHz. The images were stacked, filtered, and fit with a gray-body dust model to isolate the thermal Sunyaev-Zel'dovich (tSZ) signal, which is proportional to the total energy contained in the CGM of the galaxies. We separate these $M_{\star} = 10^{10.9} M_\odot$ - $10^{12} M_\odot$ galaxies into 0.1 dex stellar mass bins, detecting tSZ per bin up to $5.6\sigma$ and a total signal-to-noise ratio of $10.1\sigma$. We also detect dust with an overall signal-to-noise ratio of $9.8\sigma$, which overwhelms the tSZ at 150GHz more than in other lower-redshift studies. We correct for the $0.16$ dex uncertainty in the stellar mass measurements by parameter fitting for an unconvolved power-law energy-mass relation, $E_{\rm therm} = E_{\rm therm,peak} \left(M_\star/M_{\star,{\rm peak}} \right)^\alpha$, with the peak stellar mass distribution of our selected galaxies defined as $M_{\star,{\rm peak}}= 2.3 \times 10^{11} M_\odot$. This yields an $E_{\rm therm,peak}= 5.98_{-1.00}^{+1.02} \times 10^{60}$ erg and $\alpha=3.77_{-0.74}^{+0.60}$. These are consistent with $z \approx 0$ observations and within the limits of moderate models of active galactic nuclei (AGN) feedback. We also compute the radial profile of our full sample, which is similar to that recently measured at lower-redshift by Schaan et al. (2021).