Discovery of Recombining Plasma in the Supernova Remnant 3C 391
Discovery of Recombining Plasma in the Supernova Remnant 3C 391
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DOI：
10.1093/pasj/psu120
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发表时间：
2014-09
期刊：
影响因子：
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通讯作者：
Tamotsu Sato;K. Koyama;Tadayuki Takahashi;H. Odaka;S. Nakashima
中科院分区：
文献类型：
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作者：
Tamotsu Sato;K. Koyama;Tadayuki Takahashi;H. Odaka;S. Nakashima
最近对中年超新星遗迹（SNRs）的X射线研究揭示了与过电离等离子体相关的强辐射复合连续谱（RRC），其起源仍然不确定。我们报告我们发现的RRC在中年SNR 3C 391。如果用碰撞电离平衡（CIE）下的双温等离子体模型拟合X射线谱，则发现Si XIV Ly α线在2.006 keV处、S XVI Ly α线在2.623 keV处和Si XIII的RRC边缘在2.666 keV处有残留，用CIE等离子体和重组等离子体（RP）组成的复合模型能更好地描述X射线谱。丰度模式表明，RP是从一个核心坍缩的超新星与15个太阳质量的祖星星的喷出物。在被密集分子云包围的东南区和西北区，重组等离子体参数没有显著差异。我们还发现了来自SNR东南区域的6.4 keV（~2.4 sigma检测）处的Fe I K α线的提示。
Recent X-ray study of middle-aged supernova remnants (SNRs) reveals strong radiative recombination continua (RRCs) associated with overionized plasmas, of which the origin still remains uncertain. We report our discovery of an RRC in the middle-aged SNR 3C 391. If the X-ray spectrum is fitted with a two-temperature plasma model in collisional ionization equilibrium (CIE), residuals of Si XIV Ly alpha line at 2.006 keV, S XVI Ly alpha line at 2.623 keV and the edge of RRC of Si XIII at 2.666 keV are found. The X-ray spectrum is better described by a composite model consisting of a CIE plasma and a recombining plasma (RP). The abundance pattern suggests that the RP is associated to the ejecta from a core-collapse supernova with a progenitor star of 15 solar mass. There is no significant difference of the recombining plasma parameters between the southeast region and the northwest region surrounded by dense molecular clouds. We also find a hint of Fe I K alpha line at 6.4 keV (~2.4 sigma detection) from the southeast region of the SNR.