IRAS observations of collisionally heated dust in Large Magellanic Cloud supernova remnants

Abstract

IRAS additional observations are presented which show that luminous (10 4-10 5 L©) far-infrared sources are associated with the Large Magellanic Cloud supernova remnants N63A, N49, N49B, and N186D. Comparison of the infrared and X-ray data shows that a substantial fraction of the infrared emission from three of the remnants can be accounted for by collisionally heated dust. The ratio of dust-grain cooling to total atomic cooling by lines, recombination, and bremsstrahlung is ~ 10 in X-ray emitting gas (T ae 10 6 K). The evolution of a supernova remnant in a two-phase interstellar medium is considered, and it is concluded that dust cooling will not dominate supernova remnant evolution, but it probably accelerates the process.