Heating and Cooling in the ISM

Abstract

A wide variety of heating and cooling processes are important at different times and places in the Galaxy. Some processes, such as cosmic ray acceleration and thermal conduction, can be considered either heating or cooling mechanisms depending upon where you look. Our discussion covered shock waves, particularly in relation to cosmic ray acceleration and supernova remnants. The roles of thermal conduction and magnetic fields in SNR evolution are especially important. We also discussed atomic and molecular processes, photoionization of the diffuse ISM, and dust.