A study of the infrared emission of galactic supernova remnants

This work aims to investigate the nature of the infrared (IR) emission of supernova remnants (SNRs), and to use this radiation to reveal the physical properties of SNRs and the gas and dust they contain. This project has been made possible only recently, following the success of the Infrared Astronomical Satellite (IRAS) in 1983. The first part of this thesis attempts to find the general characteristics of the IR emission of SNRs. A survey of the known galactic SNRs in the IRAS database has been completed. It is found that only one third of the galactic SNRs show detectable IR emission. Many remnants are confused with other galactic IR sources. The youngest SNRs exhibit spectra of relatively warm dust at ∼90 K. Older SNRs, exhibit spectra that indicate dust grains within the SNRs have temperatures spanning a range from ∼150 K to ∼30 K. Supernova remnants can not be distinguished from other galactic IR sources on the basis of their IR colors alone. The second part of this work is a detailed study of the dust within and the IR emission of a single SRN, Puppis A. The IR morphology of Puppis A and its environment reveals that the appearance of the SNR is strongly influenced by its interaction with a nearby molecular cloud. Detailed analysis of the IR emission shows that small grains (∼10 angstrom) must be present in the SNR to account for this emission observed at 12 μm and 25 μm. There is some evidence of destruction of grains within the SNR. The temperature and density of the gas in which the dust is embedded, and the geometry of the emitting regions are inferred from the IR emission at specific locations across the SNR