Abstract Details

Name: Vikram Khaire
Affiliation: Indian Institute of Space Science and Technology, Trivandrum
Conference ID: ASI2021_604
Title : Searching for the Imprints of AGN Feedback on the Lyman-alpha Forest
Authors and Co-Authors : Vikram Khaire (IIST, Trivandrum), Joseph Hennawi (UC, Santa Barbara)
Abstract Type : Oral
Abstract Category : Extragalactic Astronomy
Abstract : One of the biggest unsolved problems in galaxy formation is the physical mechanism that quenches star formation in massive galaxies, giving rise to the observed dichotomy between blue star-forming galaxies and red-and-dead ellipticals. In order to reproduce it, all modern cosmological simulations implement some variant of AGN feedback, driving powerful galactic-scale outflows that suppress star-formation in massive galaxies at late times. Simulations show that these outflows can expel baryons into the circumgalactic and intergalactic media (IGM and CGM) resulting in Mpc-scale bubbles of tenuous hot (T > 10^6 K) gas surrounding massive galaxies. Therefore the distribution of gas in the CGM and IGM and its physical conditions can provide important hints to the actual feedback mechanism. Using state-of-the-art cosmological simulations and realistic mock data, we show that the abundances of hydrogen Lyman-alpha forest lines in the IGM and around massive galaxies at impact parameters of 0.1 to 10 pMpc can provide a precision probe to the AGN feedback models. The author will also discuss the feasibility of such a study with archival Lyman-alpha forest data from the Hubble Space Telescope.