Joint Astrophysical Colloquium
Black holes in high-redshift galaxies: formation and evolution in a rapidly evolving interstellar medium
Alessandro Lupi (Università dell'Insubria)
Thursday 05/10/2023 @ 11:30, Sala Antonio Sollima (IV piano Battiferro) + remoto
The observations of high redshift quasars at z~6 and beyond tell us that massive black holes (MBHs) were already in place, with masses up to 10^10 solar masses, when the Universe was less than 1 Gyr old. According to the currently accepted framework, MBHs gain most of their mass via radiatively efficient accretion, hence we expect that they formed early in the Universe as smaller seeds. Explaining how these MBHs formed and rapidly grew is particularly challenging, in particular when we also consider that these MBHs seem overmassive compared to the local population. After highlighting the main formation mechanisms proposed to date, I will discuss how to properly address the formation and early evolution of the first seed BHs in high-redshift systems, by introducing a state-of-the-art model which is able to directly follow stars and BHs at a few tens of Msun resolution, including stellar feedback, BH accretion and feedback, and an accurate treatment of BH dynamics. I will then discuss how the subsequent evolution of a MBH seed is affected by the peculiar environmental conditions in which it forms and evolve, and the MBH-galaxy interaction over time.