SN 1006 at optical and UV wavelengths

Abstract

AbstractOptical and UV emission from SN 1006 is observed on the periphery of the SNR, particularly in the NW, and arises as material from interstellar gas is ionized behind the shock front. The shapes of the emission lines have been used to infer a shock velocity of about 2900 km s−1 and to show that the electron and ion temperatures are close to that expected from standard shock theory. The combination of the shock velocity and the proper motion of the filaments in the NE accurately locates SN1006 at a distance of 2.2 kpc, some 550 pc above the Galactic plane. At UV wavelengths, ejecta from SN 1006 have also been observed as broad absorption lines from Si, Ca and Fe in spectra of the Schweitzer-Middleditch star and two quasars. The observations appear to limit the mass of Fe in SN 1006 to less than 0.16 M⊙, much less than expected from models of Type Ia supernovae. In this brief review of the UV and optical properties of SN 1006, I will summarize how these observations yield a fairly consistent description of SN 1006, and suggest what further observations might be undertaken to extend our understanding of SN 1006 in its second millennium.