DISCOVERY OF ENHANCED RADIATIVE RECOMBINATION CONTINUA OF He-LIKE IRON AND CALCIUM FROM IC 443 AND ITS IMPLICATIONS
DISCOVERY OF ENHANCED RADIATIVE RECOMBINATION CONTINUA OF He-LIKE IRON AND CALCIUM FROM IC 443 AND ITS IMPLICATIONS
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DOI：
10.1088/0004-637x/784/1/74
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发表时间：
2014-03
期刊：
影响因子：
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通讯作者：
T. Ohnishi;H. Uchida;T. Tsuru;K. Koyama;K. Masai;M. Sawada
中科院分区：
文献类型：
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作者：
T. Ohnishi;H. Uchida;T. Tsuru;K. Koyama;K. Masai;M. Sawada
我们用铃鹿X射线卫星对银河系超新星遗迹IC443进行了深入的观测。我们从铁和镍中发现了突出的K壳线，以及8-10keV的三角形残留物，这相当于类氦铁的辐射复合连续谱(RRC)的能量。此外，在∼5.1keV和∼5.5keV处还观察到了波状残差。我们证实，残留物显示了在超新星遗迹中发现的第一批增强的类氦和类氢钙的RRC。这些事实为重组等离子体提供了强有力的证据。在电子温度为0.65keV时，用复合等离子体模型重现了3.7-10keV波段的等离子体。复合参数Net(Ne是电子密度，t是形成复合等离子体后经过的时间)与铁和镍的丰度有很强的相关性，因此误差很大。另一方面，镍和铁相对于太阳丰度的比率很好地限制在11(1σ)。一种可能性是，大丰度比是前身恒星不对称爆炸的结果。
We present deep observations of the Galactic supernova remnant IC 443 with the Suzaku X-ray satellite. We find prominent K-shell lines from iron and nickel, together with a triangle residual at 8–10 keV, which corresponds to the energy of the radiative recombination continuum (RRC) of He-like iron. In addition, the wavy residuals have been seen at ∼5.1 and ∼5.5 keV. We confirm that the residuals show the first enhanced RRCs of He- and H-like calcium found in supernova remnants. These facts provide robust evidence for the recombining plasma. We reproduce the plasma in the 3.7–10 keV band using a recombining plasma model at the electron temperature 0.65 keV. The recombination parameter net (ne is electron density and t is elapsed time after formation of a recombining plasma) and abundances of iron and nickel are strongly correlated, and hence the errors are large. On the other hand, the ratio of nickel to iron relative to the solar abundances is well constrained to 11 (1σ). A possibility is that the large abundance ratio is a result of an asymmetric explosion of the progenitor star.