Three Dimensional Molecular Line Transfer Study of Extragalactic ISM : AGN/Starburst Connection

TL;DR

This paper develops a 3D non-LTE line transfer model to analyze molecular gas in external galaxies, aiming to distinguish between AGN and starburst activity using millimeter and submillimeter line ratios.

Contribution

It introduces a novel 3D non-LTE line transfer code as a theoretical tool to interpret high-resolution molecular line observations of extragalactic ISM.

Findings

Line ratios can differentiate between AGN and starburst activity.

The model prepares for interpreting ALMA observations.

Provides insights into the energy sources in galaxy centers.

Abstract

Molecular gas in external galaxies is a subject of crucial importance for observational and theoretical studies of galaxy formation. Compact molecular gas around an active galactic nuclei (AGN) is expected to be an energy budget of AGN and/or nuclear starburst. Recent observational studies suggest that line ratios in millimeter and submillimeter band may be a good tool to reveal the long-standing question on the origin of activity -- AGN or nuclear starburst. We have constructed a powerful "telescope" of theory, three-dimensional nonLTE line transfer code, preceding the high resolution and sensitivity observations such as ALMA.