Unveiling the Missing Baryons through the kinematic Sunyaev–Zel’dovich Effect — Bernardita Ried Guachalla (Stanford University)

Scattering of cosmic microwave background (CMB) photons by moving electrons in galactic halos produces a Doppler boost signal. This effect, once limited to clusters, now enables the detection of the “missing baryons” and constrains feedback in galaxies and groups through stacking analyses. Rapid progress in survey science, microwave experiments such as the Atacama Cosmology Telescope and the Simons Observatory, together with optical surveys like the Dark Energy Spectroscopic Instrument and the Vera C. Rubin Observatory, is driving breakthroughs in this field. I will present my work on improved modeling (Ried Guachalla et al. 2024) and one of the most sensitive measurements to date (Ried Guachalla et al. 2025). We find that gaseous halos of galaxy groups extend well beyond their dark matter halos, suggesting feedback processes stronger than hydrodynamical simulations predict.

Horarios: Octubre 2, 11:30

Publicado por: Gijs Mulders