8-12 juin, 2014


AGN feedback models: Correlations with star formation and observational implications of time evolution

Robert Thacker (Saint Mary's University)

C MacMackin, J Wurster & A Hobbs

While observational ensemble statistics, focusing especially on the star formation rates (SFR) and black hole accretion rates (BHAR), sometimes use sample averaging to capture variations in the BHAR with time, we instead pose the question: how would correlations appear if the intrinsic time variation of a single halo was sampled? We hence examine the correlations of star formation and AGN activity, and the associated time evolution, across seven different AGN models, three different stages of evolution and two distinct sub-populations of star formation, for a total of 63 different cases. Despite many of the models fitting the M-sigma relationship well, we find markedly different behaviour across models when examined in these new SFR-BHAR contexts. Importantly, some of the models show evolution in the SFR-BHAR parameter space that is diametrically across the averaged SFR-BHAR trend, suggesting that such relationships are less about a direct physical relationship and more an approximate statistical trend, as suggested by Hickox etal. We also find distinct differences in post-starburst black hole mass growth. These results again highlight the challenges in accurately predicting black hole mass growth and feedback in simulations of galaxy formation.
(doit être confirmé par le SOC)