Orateur
Description
The Sunyaev-Zel’dovich 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), where electrons have high energies due to their temperature, and which probes the electron integrated pressure. These two effects 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 describe the evolution of the large scale structure in our Universe. Both tSZ and kSZ can be measured in cross-correlation with large-scale structure.
In this talk, I will show my ongoing measurements of the tSZ-galaxy cross-correlation using unWISE galaxies with the newest ACT DR6 data, along with the measured kSZ signal of unWISE galaxies with Planck using the projected-field estimator (which does not require spectroscopic redshift information of the galaxy sample). unWISE is a galaxy catalog, which consists of three subsamples of mean redshifts z=0.5, 1.1, 1.5 and contains over 500 million galaxies on the full sky, and whose halo occupation distribution I have already constrained. The tSZ-galaxy cross-correlation measurement will be the highest SNR to date. I will also discuss the prospects of combining both measurements and applying the method to other galaxy samples.
