Launching galactic outflows with AGN winds and radiation

Speaker: Dr. Tiago Costa (Max Planck Institute for Astrophysics)

Date: 2019/10/29, Tuesday, 5 pm

Room: Science hall B102

Language: English

Abstract:

Most massive galaxies in the present-day Universe have ceased to form new stars. The responsible physical mechanisms, however, remain elusive. In this talk, I will present results from a suite of cosmological, radiation-hydrodynamic simulations designed to test scenarios in which active galactic nuclei suppress star formation through `quasar feedback’. I will start by reviewing the main physical mechanisms governing quasar feedback, illustrating how processes such as radiation pressure can launch powerful galactic outflows that alter the evolution of the quasar host galaxies and their environment. I will argue that the most efficient form of quasar feedback proceeds through the collision of accretion-disc winds against the interstellar medium, forming shock-heated bubbles that push interstellar material to the outskirts of the host galaxy. I will discuss the properties of the resulting galactic outflows, showing how multi-phase structure emerges, and will quantify their impact on the host galaxy.