Extragalactic chemistry of molecular gas: lessons from the local universe
Abstract
Observational constraints provided by high resolution and high sensitivity observations of external galaxies made in the millimetre and sub-millimetre range have started to put on a firm footing the study of the extragalactic chemistry of molecular gas. In particular, the availability of multi-species and multi-line surveys of nearby galaxies is central to the interpretation of existent and forthcoming millimetre observations of the high redshift universe. Probing the physical and chemical status of molecular gas in starbursts and active galaxies (AGN) requires the use of specific