Speaker
Description
There is no consensus on how baryon feedback shapes the underlying matter distribution from either simulations or observations. We confront the uncertain landscape by jointly analyzing the kinetic and thermal Sunyaev-Zel’dovich effects and X-ray gas mass fractions, each characterized with galaxy-galaxy lensing. Across group and clusters masses and between $0<z<1$, we find consistent evidence of more efficient gas expulsion beyond the virial radius than predicted by most state-of-the-art simulations, implying significant suppression of the matter power spectrum on small scales. We incorporate these constraints into data-driven priors for cosmic shear, significantly improving cosmological constraining power on small scales. By jointly characterizing the halos’ gas density, pressure, and total matter profiles, we are revealing the physical mechanism of baryon feedback.