Suzaku observations of tycho's supernova remnant

Abstract

Tycho's supernova remnant was observed by the XIS and HXD instruments onboard the Suzaku satellite on 2006 June 26-29 for 92 ks. The spectrum up to 30 keV was well fitted with a two-component model, consisting of a power-law with a photon index of 2.7 and a thermal bremsstrahlung model with a temperature of 4.7 keV. The former component can alternatively be modeled as synchrotron emission from a population of relativistic electrons with an estimated roll-off energy of around 1 keV. In the XIS spectra, in addition to the prominent Fe Ka line (6.445 keV), we observed for the first time significant Ka line emission from trace species Cr and Mn at energies of 5.48 keV and 5.95 keV, respectively. Faint K/5 lines from Ca (4.56keV) and Fe (7.11 keV) were also seen. The ionization states of Cr and Mn, based on their line centroids, are estimated to be similar to that of Fe Ka (Fexv orxvi).