Resolved Structure in M33 Supernova Remnants

Abstract

We present WF/PC narrow band [S II] lambda-6725 images of two M33 supernova remnants obtained with the Wide Field/Planetary Camera on the Hubble Space Telescope. Comparison of these images with ground-based CCD data indicates that HST has resolved the nebular structures into shells or partial shells, permitting improved measurements of the diameters of these objects. Ground-based echelle spectra obtained at Kitt Peak with the 4 m telescope show profiles with Half Width Zero Intensity velocities of 163 and 275 km s^-1 for the two objects, indicating rapid bulk motions of the emitting filaments. The morphology of the emission seen in the WF/PC images allows the non-Gaussian shapes of the integrated echelle profiles to be understood. We briefly compare the predicted WF/PC count rates with those actually realized and discuss the reason for the discrepancy. (SECTION: Interstellar Medium and Nebulae)