INFRARED-EMISSION FROM X-RAY AND OPTICALLY EMITTING REGIONS IN THE CYGNUS LOOP SUPERNOVA REMNANT

We present a new technique for analyzing the infrared (IR) emission of a supernova remnant (SNR) and apply it to the Cygnus Loop. The technique consists of a decomposition of the IR emission from the remnant (in all four IRAS bands) into two distinct emission components. The first component is spatially correlated with the X-ray emission from the remnant and arises from collisionally heated dust in the shocked gas. The second component is spatially correlated with the optical filaments and arises from dust which is radiatively or collisionally heated within the filaments, and from IR lines emitted by the shocked gas. The decomposition allows us to determine the characteristics of the dust, examine evidence for grain processing through the shock, 'constrain various remnant parameters, and demonstrate how the morphology of the environment determines the IR emission from the remnant.