On the Formation of Over-ionized Plasma in Evolved Supernova Remnants
On the Formation of Over-ionized Plasma in Evolved Supernova Remnants
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DOI：
10.3847/1538-4357/ac8cf9
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发表时间：
2022-08
期刊：
影响因子：
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通讯作者：
M. Katsuragawa;Shiu-Hang Lee;H. Odaka;A. Bamba;H. Matsumura;Tadayuki Takahashi
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文献类型：
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作者：
M. Katsuragawa;Shiu-Hang Lee;H. Odaka;A. Bamba;H. Matsumura;Tadayuki Takahashi
围绕超新星遗迹（SNRs）中发现的丰富多样性的一个突出谜团是最近发现的过度电离或重组等离子体，这些等离子体来自许多动态演化的物体。为了帮助破译其形成机制，我们开发了一个新的模拟框架，能够模拟在信噪比下等离子体电离状态的时间演变。该平台基于一维流体力学代码与完全依赖于时间的非平衡电离计算相结合，并伴有光谱合成代码，以生成任意年龄信噪比的空间分辨宽带x射线光谱。我们进行了一项全面的参数调查，以研究不同的星周环境对SNRs中电离状态演变的影响，该影响可达104年。由星际介质（ISM）密度阵列和祖星的质量损耗率所跨越的二维参数空间用于创建周围环境的模型网格，其中触发了核心坍塌爆炸。我们的研究结果表明，年轻的信噪比（100 ~ 1000年）在空间扩展的低密度风中快速膨胀，老的信噪比（100 ~ 1000年）在密集的ISM中膨胀，或者老的信噪比从狭窄的密集风区爆发到脆弱的ISM中，都可以成功地再现重组等离子体。最后，我们的模型面对进化的信噪比的观测结果，除了几个异常值外，发现总体上很一致。
One of the outstanding mysteries surrounding the rich diversity found in supernova remnants (SNRs) is the recent discovery of over-ionized or recombining plasma from a number of dynamically evolved objects. To help decipher its formation mechanism, we have developed a new simulation framework capable of modeling the time evolution of the ionization state of the plasma in an SNR. The platform is based on a one-dimensional hydrodynamics code coupled to a fully time-dependent nonequilibrium ionization calculation, accompanied by a spectral synthesis code to generate space-resolved broadband X-ray spectra for SNRs at arbitrary ages. We perform a comprehensive parametric survey to investigate the effects of different circumstellar environments on the ionization state evolution in SNRs up to a few 104 yr. A two-dimensional parameter space, spanned by arrays of interstellar medium (ISM) densities and mass-loss rates of the progenitor, is used to create a grid of models for the surrounding environment, in which a core-collapse explosion is triggered. Our results show that a recombining plasma can be successfully reproduced in the case of a young SNR (a few 100 to 1000 yr old) expanding fast in a spatially extended low-density wind, an old SNR (>a few 1000 yr) expanding in a dense ISM, or an old SNR broken out from a confined dense wind region into a tenuous ISM. Finally, our models are confronted with observations of evolved SNRs, and an overall good agreement is found except for a couple of outliers.