Island universes colliding

Abstract

Galaxies do not spend their whole lives in isolation. In fact, interactions and merger events are very important in galaxy evolution, even more so at high redshift, where the number-density of galaxies was considerably higher than it is today. These encounters often trigger a burst of star formation. We use high spatial resolution mid-infrared observations of nearby starburst galaxies to develop a detailed understanding of this starburst phenomenon and the resulting stellar populations. The issues addressed are the properties of superstarclusters, the nature of extreme star formation in (Ultra) Luminous Infrared Galaxies ((U)LIGs), and the characteristics of nuclear starburst rings in barred galaxies. In this paper we present the first mid-infrared imaging and spectroscopy obtained with VISIR at the ESO Very Large Telescope.