Obscured Active Galactic Nuclei triggered in compact star-forming galaxies
Abstract
We present a structural study of 182 obscured Active Galactic Nuclei (AGNs) at z<=1.5, selected in the COSMOS field from their extreme infrared to X-ray luminosity ratio and their negligible emission at optical wavelengths. We fit optical to far-infrared spectral energy distributions and analyze deep HST imaging to derive the physical and morphological properties of their host galaxies. We find that such galaxies are more compact than normal star-forming sources at similar redshift and stellar mass, and we show that it is not an observational bias related to the emission of the AGN. Based on the distribution of their UVJ colors, we also argue that this increased compactness is not due to the additional contribution of a passive bulge. We thus postulate that a vast majority of obscured AGNs reside in galaxies undergoing dynamical compaction, similar to processes recently invoked to explain the formation of compact star-forming sources at high redshift.
Cite
@article{arxiv.1612.02429,
title = {Obscured Active Galactic Nuclei triggered in compact star-forming galaxies},
author = {Yu-Yen Chang and Emeric Le Floc'h and Stéphanie Juneau and Elisabete da Cunha and Mara Salvato and Francesca Civano and Stefano Marchesi and J. M. Gabor and Olivier Ilbert and Clotilde Laigle and H. J. McCracken and Bau-Ching Hsieh and Peter Capak},
journal= {arXiv preprint arXiv:1612.02429},
year = {2017}
}
Comments
Accepted for publication in MNRAS Letter