Multiple-line study of NGC 1068: Hot molecular gas caused by jet-gas interaction in the central 100pc?

Abstract

A multiple molecular line and line transition study is presented for the circumnuclear disk (CND) of the proto-typical Seyfert galaxy NGC 1068. A detailed analysis of the kinematics and excitation conditions of the molecular gas, as traced by 12CO, 13CO, HCN and HCO+, suggests that part of the molecular gas in the CND is shocked, expanding and heated to high kinetic temperatures most likely as a consequence of an interaction between the radio jet and the CND. We further find support for an X-ray altered chemistry of the molecular gas in the CND based on the significantly elevated abundance of HCN when compared to star-forming, starbursting or quiescent gas regions.