The BeppoSAX X-ray spectrum of the remnant of SN 1006

Abstract

We present BeppoSAX X-ray spectra of the remnant of the supernova of AD 1006, which cover a broad spectral range of 0.1-10 keV. In our analysis we concentrate on the thermal emission from the central region of the remnant. For this purpose we fitted the spectra of the whole remnant using a new version of the spectral program SPEX, which takes into account the interdependence of spectra of different regions as the result of the point spread function of the instruments. This is in particular important for separating the synchrotron emission, coming from the bright rims of the remnant, from the thermal emission from the central regions. The thermal emission appears best fitted with a combination of two spectral components with electron temperatures of about 0.7 keV and more than 3 keV. The plasma in SN 1006 appears to be very far out of ionization equilibrium (nt = 2 10^15 m^-3 s), which means that the L-shell emission of magnesium, silicon and sulphur contribute significantly to the flux below 0.5 keV. We also note the presence of Fe K line emission at 6.3+/-0.2 keV, in agreement with an origin from inner shell ionizations and excitations. We confirm that the abundances in SN 1006 are clearly non-solar. In particular silicon is very abundant. We did not find substantial variations in plasma properties over the face of the remnant, although the hotter component seems more dominant in the Northern half of the remnant.