Probing the Ionized Gas Thermodynamicsin Distant Galaxieswith the Sunyaev-Zel'dovich Effect*

The Sunyaev-Zel’dovich (SZ) Effect—the Doppler boost of low energy Cosmic Microwave Background photons scattering off free electrons—is an excellent probe of ionized gas residing in distant galaxies. Its two constituents are the kinematic SZ effect (kSZ), where electrons have a non-zero line-of-sight (LOS) velocity and which probes the electron line-of-sight momentum, and the thermal SZ effect (tSZ) effect, where electrons have high energies due to their temperature, and which probes the electron integrated pressure. These two effects, together with lensing measurement (which scales as the total integrated mass along the LOS), provide complementary information to constrain the thermodynamic profile of the gas residing in distant galaxies, which can be further used to understand feedback processes, a necessary ingredient to understand the evolution of LSS in our Universe. 

I measured the kSZ signal of unWISE galaxies with the projected-field estimator, which does not require spectroscopic redshift information. unWISE is a galaxy catalog consisting of three samples of mean redshifts z=0.5, 1.1, 1.5 and containing over 500 million galaxies on the full sky. I will also discuss the preliminary tSZ measurement of for unWISE, along with the Halo Occupation Distribution of these galaxies.