Title: Atomic Cooling Halos from Decaying Dark Matter
Abstract: The evolution of pre-star-forming halos provides a new channel to probe dark matter interactions with the Standard Model. A key aspect of halo evolution is their cooling mechanism, which relies on molecular hydrogen in the conventional scenarios. Energy injection from the dark sector can significantly alter halo cooling by modifying the hydrogen abundance and trigger atomic cooling halos. In this talk, I will use axion as an example to illustrate the impact of decaying dark matter on early halos. The decay of eV-scale axion into photons can prevent molecular hydrogen formation, thus suppressing the formation of Population III stars and potentially enabling the direct collapse of halos to address the origin of supermassive black holes. I will show that this sets new bounds on axion couplings that are competitive with existing constraints.
Zoom link: https://umd.zoom.us/j/95913933745?pwd=qCekrni5KRyBoypxAEJS9xE1drb05A.1
ID: 959 1393 3745
Passcode: UMDEPT