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Physics & Astronomy Colloquium
November 16, 2016 @ 3:45 pm - 5:00 pmFree
Speaker: Dominika Wylezalek
Title: Signatures of Black Hole feedback
Abstract: Supermassive black holes (SMBH) are some of the most mysterious objects that astronomers have tried to understand theoretically and observationally for over 100 years. Amazingly, SMBHs are now thought to be hosted by every galaxy in the Universe. Intriguingly, feedback from actively accreting SMBHs (Active Galactic Nuclei, AGN) is now widely considered to be the main driver in regulating the growth of massive galaxies through either heating of gas in the interstellar medium or actively driving gas out of the galaxy curtailing star formation. Observational proof for this scenario has, however, been hard to come by. Many attempts at finding conclusive observational evidence that AGN may be able to quench star formation and regulate the host galaxies’ growth have shown that this problem is highly complex.
In this talk I will present results from several projects that focus on finding concrete data-driven evidence for SMBH/galaxy self-regulation and on understanding the power, reach and impact of feedback processes exerted by AGN. New observing techniques such as integral field unit (IFU) observations that probe spatially resolved stellar and gas kinematics enable fundamentally new methods of investigating AGN feedback. I will describe recent efforts in our group of relating feedback signatures to the specific star formation rate in their host galaxies, where our results are consistent with the AGN having a `negative’ impact through feedback on the galaxies’ star formation history. Furthermore, I will show that powerful AGN-driven winds can be easily hidden and not be apparent in the integrated spectrum of the galaxy. But with large IFU surveys, such as the SDSS MaNGA survey, we might uncover many previously unknown AGN and AGN-driven outflows that are potentially very relevant for understanding the role of active black holes in galaxy evolution!
The colloquia will be preceded by light refreshments in GL227 from 3:30 – 3:45p.m.