by Serena Viti (University College London)

Abstract. It is now well established that chemistry in external galaxies is rich and complex. In this talk I will show how molecular emission from external galaxies can be used to explore and characterize the physical conditions and energetics of these galaxies, as well as, possibly, their evolutionary status. I will present examples of the chemical and radiative transfer models that have been developed in recent years to tackle the often unresolved (spatially and spectrally) extragalactic molecular emission. I will then show recent applications of such models in nearby galaxies and how to make molecules into powerful diagnostics of the evolution and distribution of molecular gas.