X-Ray Spectroscopy of SN 1006 with Suzaku

Hiroya Yamaguchi, Katsuji Koyama, Satoru Katsuda, Hiroshi Nakajima, John P. Hughes, Aya Bamba, Junko S. Hiraga, Koji Mori, Masanobu Ozaki, Takeshi Go Tsuru
2008 Nippon Tenmon Gakkai obun kenkyu hokoku  
We report on observations of SN 1006 with the X-ray Imaging Spectrometers (XIS) on board Suzaku. We firmly detected K-shell emission from Fe, for the first time, and find that the Fe ionization state is quite low. The broad band spectrum extracted from the southeast of the remnant is well fitted with a model consisting of three optically thin thermal non-equilibrium ionization plasmas and a power-law component. Two of the thermal models are highly overabundant in heavy elements and, hence, are
more » ... ikely due to ejecta. These components have different ionization parameters: n_et ∼ 1.4× 10^10 cm^-3 s and n_et ∼ 7.7× 10^8 cm^-3 s and it is the later one that produces the Fe-K emission. This suggests that Fe has been heated by the reverse shock more recently than the other elements, consistent with a picture where the ejecta are stratified by composition with Fe in the interior. On the other hand, the third thermal component is assumed to be solar abundance, and we associate it with emission from the interstellar medium (ISM). The electron temperature and ionization parameter are kT_e ∼ 0.5 keV and n_et ∼ 5.8× 10^9 cm^-3 s. The electron temperature is lower than that expected from the shock velocity which suggests a lack of collisionless electron heating at the forward shock. The extremely low ionization parameter and extreme non-equilibrium state are due to the low density of the ambient medium.
doi:10.1093/pasj/60.sp1.s141 fatcat:djyu5xeqgrepjjdfa2lzrrjgdm