RSAA Colloquia / Seminars / Feast-of-Facts: Tuesday, 27 October 2015, 11:00-12:00; Duffield Lecture Theatre

Rebecca Davies

"Dissecting Galaxies - Separating Emission Excited by Star Formation and AGN Activity"

The spectra of AGN host galaxies contain emission lines excited by radiation from both massive stars and the AGN accretion disk. Standard calibrations for the star formation rate, AGN accretion rate and the physical conditions of the line-emitting gas are not applicable to such composite spectra, imposing significant limitations on studies of the physical processes driving the evolution of AGN host galaxies. In this talk I will explain how integral field spectroscopy can be combined with emission line ratio diagnostic diagrams to separate star formation, AGN activity (and shock excitation!), both spatially and in their absolute contributions to individual velocity components of individual emission lines. I will present the first 2D maps of the star formation rates across AGN host galaxies without contamination from the AGN, and the first maps of the narrow line region emission without contamination from star formation. The ability to separate star formation and AGN activity will offer unprecedented insights into the starburst-AGN connection, both locally and at higher redshifts.