Tuesday 28 July at 3pm

Vassilis Charmandaris - Observatoire de Paris, DEMIRM

"The Mid-IR view of collisionally induced star formation in interacting galaxies"

ABSTRACT:"Galaxy interactions, used as `cosmic experiments', provide an ideal laboratory for the study of star formation. Tidal effects cause major redistribution of the interstellar gas of the interacting galaxies leading to the formation of large scale star-forming complexes, over regions where the gas and dust density as well as the intensity of the radiation field vary substantially. A sample of nearby interacting galaxies has been imaged in the mid-IR by ISOCAM. It has been discovered that collisionally induced star forming regions heat the gas and dust in the interstellar medium of those galaxies producing a rich mid-IR spectrum. I will present the current status of our analysis and interpretation of the data focusing on four cases. Two systems which are in the early stages of interaction : The Antennae (NGC 4038/39) and the Cartwheel and two merger remnants: NGC 6240 and Arp 220. I will discuss the implications of these observations in the framework of our up-to-date knowledge on these systems and describe our future plans."