We present the results of a spectral analysis of the central region of the mixed-morphology supernova remnant HB 9. A prior Ginga observation of this source detected a hard X-ray component above 4 keV and the origin of this particular X-ray component is still unknown. Our results demonstrate that the extracted X-ray spectra are best represented by a model consisting of a collisional ionization equilibrium plasma with a temperature of ~0.1-0.2 keV (interstellar matter component) and an ionizing plasma with a temperature of ~0.6-0.7 keV and an ionization timescale of >1 x 10^{11} cm^{-3} s (ejecta component). No significant X-ray emission was found in the central region above 4 keV. The recombining plasma model reported by a previous work does not explain our spectra.

中文翻译：

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来自混合形态超新星遗迹 HB 9 的 X 射线发射

我们展示了混合形态超新星遗迹 HB 9 中心区域的光谱分析结果。对该源的先前 Ginga 观测检测到高于 4 keV 的硬 X 射线分量，并且该特定 X 射线分量的起源是还是个未知数。我们的结果表明，提取的 X 射线光谱最好由温度为 ~0.1-0.2 keV（星际物质成分）的碰撞电离平衡等离子体和温度为 ~0.6-0.7 keV 的电离等离子体组成的模型表示以及 >1 x 10^{11} cm^{-3} s（喷射成分）的电离时间尺度。在高于 4 keV 的中心区域没有发现显着的 X 射线发射。先前工作报告的重组等离子体模型并不能解释我们的光谱。