UHM Physics Department Colloquia

Insights into galaxy assembly from luminous AGN in the distant Universe

by Prof. Duncan Farrah (Virginia Tech)

112 (Watanabe Hall)


Watanabe Hall

2505 Correa Road
There is a deep connection between star formation and active galactic nuclei which profoundly impacts the assembly history of galaxies across most of the history of the Universe. The nature of the connection however remains controversial, due to, for example, the uncertain evolution in, and synergy between, the AGN and starburst duty cycles, and the obscuring effect of dust. In this talk I will briefly review our current knowledge of galaxy assembly, and then discuss two recent results. First is an observed scaling relation between star formation rates and AGN luminosities in luminous type 1 quasars at high redshift, as determined using data from the Herschel and Spitzer space telescopes. This relation offers insights into how star formation is triggered and quenched in luminous quasars, and how stellar mass assembly proceeds in AGN hosts towards the end of the AGN duty cycle. Second is a study, using both the Hubble Space Telescope and Herschel, on the most luminous obscured AGN in the Universe. The nature of these AGN offers extremely stringent tests of galaxy evolution models. I will discuss the morphologies of their host galaxies, and show that they signpost a brief but critical phase in galaxy evolution.
downloadable video