Oral Presentation

Cold molecular gas observations toward nearby luminous AGNs

Author(s): Takuma Izumi (NAOJ)

Presenter: Takuma Izumi (NAOJ)

I will introduce the following 'two' ALMA programs of cold molecular gas observations toward nearby luminous (L_bol > 10^43 erg/s) active galactic nuclei (AGNs).

(1) multi-J CO and C observations toward NGC 7469: we investigated detailed gas distribution and excitation around the nucleus of this type-1 Seyfert galaxy. We found that [CI](1-0)/CO (multi-J) line ratio is incredibly high at the nucleus as compared to star-forming regions of this galaxy. This enhancement is interpreted as a consequence of complex gas excitation (e.g., opacity) and abundance variation of C in an "Xray dominated region (XDR)" created by this AGN.

(2) ALMA-BASS: we performed ~100 pc resolution CO(2-1) imaging survey toward 33 luminous AGNs selected from the Swift/BAT AGN Spectroscopic Survey (BASS). The line emission was successfully detected from most of the targets. I will discuss statistical properties of CO luminosity, gas distribution (central concentration), and relationship between the molecular gas amount of the ~100 pc-scale circumnuclear disk and the AGN power itself.