The most luminous AGN in the Universe are not preferentially triggered by mergers
Abstract
We present results from a combined HST, Herschel, Spitzer and WISE study of twelve obscured AGN at 1.8 < z < 2.7 with infrared luminosities of (2-15) x 10^13 Solar. These luminosities make the sample among the most luminous objects known, at any redshift. In all cases in the infrared emission arises at least mostly from AGN activity. Adopting the G, M20, and A morphological parameters, together with traditional classification boundaries, infers that three-quarters of the sample are mergers. Our sample does not, however, show any correlation between the considered morphological parameters and either infrared luminosity or AGN fractional luminosity. Moreover, the asymmetries and effective radii of our sample are distributed identically to those of massive galaxies at z ~ 2. We conclude that our sample is not preferentially associated with mergers, though a significant merger fraction is still plausible. Instead, we propose that our sample includes examples of the massive galaxy population at z ~ 2 that harbor a briefly luminous, “flickering” AGN and in which the G and M 20 values have been perturbed due to either the AGN and/or the earliest formation stages of a bulge in an inside-out manner. Furthermore, we find that the mass assembly of the central black holes in our sample leads the mass assembly of any bulge component.
- Publication:
-
American Astronomical Society Meeting Abstracts #231
- Pub Date:
- January 2018
- Bibcode:
- 2018AAS...23130406F