Einstein Observations of the SNRs IC443, W44 and W49B

Abstract

We present soft x-ray observations made with the Einstein Observatory Imaging Proportional Counter (IPC) of IC443, W44 and W49B (for details of the observatory and instruments see Giacconi et al. 1979). The x-ray emission from IC443 and W44 is clearly concentrated within the interior of the remnant with little or no evidence for a limb-brightened shell. Significant spectral differences are found across the x-ray images in both remnants which are interpreted as being due to a combination of differential absorption by molecular clouds and intrinsic spatial temperature variations. The distant remnant W49B is only just resolved in the IPC observations, but additional observations with the High Resolution Imager (HRI) indicate a similar “infilled” morphology to IC443 and W44.