A detailed X-ray and radio comparison of Kepler's supernova remnant

Abstract

High-resolution radio images of Kepler's SNR (SN 1604) at 6 and 21 cm have been obtained using the VLA. The orientation of linear polarization in the SNR implies a substantial nonrandom radial component for the magnetic field of the remnant. Based on a new X-ray picture of the SNR, obtained using the Einstein Observatory, we have carried out a detailed comparison of the X-ray and radio morphology. There is a good correlation between rotation measure, obtained from the radio maps, and emission measure, an X-ray derived quantity in the SNR shell. From the mean electron density (