TUNA Lunch Talk:

Christy Pierce


AGNs and Merging Galaxies at z~1: Causes and Effects of Black Hole Growth

January 20

3:10PM, Room 230, NRAO, Edgemont Road


I have investigated the causes and effects of AGNs by studying the color and morphology characteristics of their host galaxies. AGNs were selected based on X-ray luminosities, radio powers, and/or optical spectra. It was found that AGN host galaxies are more likely than galaxies in corresponding control samples to be morphologically classified as interacting, early-type, bulge-dominated, and/or E/S0/Sa, suggesting that they are currently interacting or may have undergone a merger in the recent past. AGN hosts were not more likely to have a close kinematic companion, potentially restricting the intial start of significant nuclear activity to well into the interaction. Simulations used to test the reliability of the color and morphology measurements used here indicated that the measurements are potentially sensitive to low-luminosity contributions from AGNs, but that the AGN should also become visible as an optical point source at these low luminosities, and so would be identifiable as a potential source of contamination.