Separating Thermal and Nonthermal X‐Rays in Supernova Remnants. II. Spatially Resolved Fits to SN 1006 AD

We present a spatially resolved spectral analysis of full ASCA observationsof the remnant of the supernova of 1006 AD. This remnant shows both nonthermalX-ray emission from bright limbs, generally interpreted as synchrotron emissionfrom the loss-steepened tail of the nonthermal electron population alsoresponsible for radio emission, and thermal emission from elsewhere in theremnant. In earlier work, we showed that the spatially integrated spectrum waswell described by a theoretical synchrotron model in which shock accelerationof electrons was limited by escape, in combination with thermal modelsindicating high levels of iron from ejecta. Here we use new spatially resolvedsubsets of the earlier theoretical nonthermal models for the analysis. We findthat emission from the bright limbs remains well described by those models, andrefine the values for the characteristic break frequency. We show thatdifferences between the northeast and southwest nonthermal limbs are small, toosmall to account easily for the presence of the northeast limb, but not thesouthwest, in TeV gamma-rays. Comparison of spectra of the nonthermal limbs andother regions confirms that simple cylindrically symmetric nonthermal modelscannot describe the emission, and we put limits on nonthermal contributions toemission from the center and the northwest and southeast limbs. We can rule outsolar-abundance models in all regions, finding evidence for elevatedabundances. However, more sophisticated models will be required to accuratelycharacterize these abundances.Comment: 14 pages, emulateapj, accepted ApJ January 10, 200