Oral Presentation

Structures of AGN Host Galaxies

Author(s): Yu-Yen Chang (ASIAA) et al.

Presenter: Yu-Yen Chang (ASIAA)

I will present our results on mid-infrared selected active galactic nuclei (AGNs) in the COSMOS field. We derived their stellar masses, star formation rates, dust properties, AGN contributions, and obscurations by fitting their optical to far-infrared photometry through the state-of-art spectral energy distribution technique. We confirm our previous finding about compact host galaxies of obscured AGNs at z~1, and find that galaxies with 20-50% AGN contributions tend to have smaller sizes, by~25-50%. Besides, we show that disturbed feature fraction has dependence on the total and star-forming infrared luminosity, rather than the decomposed AGN infrared luminosity. Our results suggest that major merger is not the main driver of AGN activities, and obscured AGNs might be triggered by internal mechanisms, such as secular process, disk instabilities, and compaction in a particular evolutionary stage. I will also show our recent results about AGN sizes based on the latest data from ALMA observations.