Hiroya Yamaguchi, Katsuji Koyama, Hiroyuki Uchida
We report on results of imaging and spectral analysis of the supernova
remnant (SNR) RCW 86 observed with Suzaku. The SNR is known to exhibit K-shell
emission of low ionized Fe, possibly originating from supernova ejecta. We
revealed the global distribution of the Fe-rich plasma in the entire remnant,
for the first time; the Fe-K emission was clearly detected from the west,
north, and south regions, in addition to the X-ray brighter shells of southwest
and northeast, where the presence of the Fe-rich ejecta has already been
reported. The spectrum of each region is well represented by a three-component
model consisting of low- and high-temperature thermal plasmas and a non-thermal
emission. The lower-temperature component, with elemental abundances of near
the solar values, likely originates from the forward shocked interstellar
medium, while the Fe-rich ejecta is described by the hotter plasma. From the
morphologies of the forward and reverse shocks in the west region, the total
ejecta mass is estimated to be 1-2M_sun for the typical explosion energy of ~ 1
x 10^{51} erg. The integrated flux of the Fe-K emission from the entire SNR
roughly corresponds to a total Fe mass of about 1M_sun. Both of these estimates
suggest a Type Ia supernova origin of this SNR. We also find possible evidence
of an Fe-rich clump located beyond the forward-shock front in the north rim,
which is reminiscent of ejecta knots observed in the Tycho and Vela SNRs.
View original:
http://arxiv.org/abs/1202.1594
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