A multi-phased study of outflows in active galaxies

by Ms. Dalya Baron

Tau

at Astrophysics and Cosmology Seminar

Wed, 04 Nov 2020, 11:10
Sacta-Rashi Building for Physics (54), room 207

Abstract

One of the most fascinating discoveries in modern astronomy is that all massive galaxies host supermassive black holes (SMBHs) in their center, with masses that are proportional to the stellar mass in their hosts. This discovery has led to a suggestion that the growth of SMBHs is linked to the stellar mass growth in their hosts. To reproduce the observed correlation, galaxy formation models often invoke a “feedback” process, in which an accreting SMBH drives massive outflows that prevent additional gas accretion onto the SMBH, switch-off star formation in the host galaxy, and enrich the circumgalactic medium with metals. Despite the great success of such models in reproducing many observed properties of massive galaxies, observing this feedback in action has proven to be very challenging. The mass and energy that are carried by the outflow have been estimated only in a handful of systems, and even these estimates are highly uncertain and biased. In this talk I will present an analysis of outflow properties in the largest sample of active galaxies to date. Using novel methods we developed to constrain key outflow properties, we were able to study the multi-phased nature of the outflows and estimate the mass and energy that are carried out by the winds. Our results suggest that these outflows are too weak to have a significant impact on their host galaxy in most of the cases, challenging the suggested feedback model for this population. I will finish the talk by discussing some unresolved issues that prevent us from drawing more concrete conclusions regarding the importance of feedback in typical active galaxies, and will show how observations of outflows in post starburst E+A galaxies can help reduce these uncertainties.

Created on 29-10-2020 by Zitrin, Adi (zitrin)
Updaded on 29-10-2020 by Zitrin, Adi (zitrin)