He-like Ions as Practical Astrophysical Plasma Diagnostics: From Stellar Coronae to Active Galactic Nuclei
He-like Ions as Practical Astrophysical Plasma Diagnostics: From Stellar Coronae to Active Galactic Nuclei
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DOI：
10.1007/s11214-010-9731-2
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发表时间：
2010-12
影响因子：
10.3
通讯作者：
D. Porquet;J. Dubau;N. Grosso
中科院分区：
文献类型：
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作者：
D. Porquet;J. Dubau;N. Grosso
本文综述了基于类氦离子谱线比的X射线等离子体诊断方法。三重线/单线强度可以用来确定电子温度和密度，最初是为了研究日冕而开发的。自从X射线卫星钱德拉和XMM-牛顿发射以来，这些诊断方法已经扩展并用于（从Cv到Sixiii）各种各样的天体物理等离子体，如恒星日冕，超新星遗迹，太阳系天体，活动星系核和X射线双星。此外，类氦离子的强度可以用来确定工作中的电离过程，以及X射线等离子体和紫外线发射源之间的距离，例如在热恒星中。在不久的将来，由于下一代X射线卫星（例如，Astro-H和IXO），高Z类He线（例如，铁）将被解决，允许探测具有更高温度和密度的等离子体。此外，所谓的卫星线，形成接近父氦样线，将提供额外的有价值的诊断，以确定电子温度，离子分数，偏离电离平衡和/或麦克斯韦电子分布。
We review X-ray plasma diagnostics based on the line ratios of He-like ions. Triplet/singlet line intensities can be used to determine electronic temperature and density, and were first developed for the study of the solar corona. Since the launches of the X-ray satellites Chandra and XMM-Newton, these diagnostics have been extended and used (from Cvto Sixiii) for a wide variety of astrophysical plasmas such as stellar coronae, supernova remnants, solar system objects, active galactic nuclei, and X-ray binaries. Moreover, the intensities of He-like ions can be used to determine the ionization process(es) at work, as well as the distance between the X-ray plasma and the UV emission source for example in hot stars. In the near future thanks to the next generation of X-ray satellites (e.g., Astro-H and IXO), higher-Z He-like lines (e.g., iron) will be resolved, allowing plasmas with higher temperatures and densities to be probed. Moreover, the so-called satellite lines that are formed closed to parent He-like lines, will provide additional valuable diagnostics to determine electronic temperature, ionic fraction, departure from ionization equilibrium and/or from Maxwellian electron distribution.