Spectral study of the Galactic ridge X-ray emission with Suzaku: Comparison of the spectral shape with point sources
Spectral study of the Galactic ridge X-ray emission with Suzaku: Comparison of the spectral shape with point sources
复制标题
用朱雀进行银脊 X 射线发射的光谱研究：与点源的光谱形状比较
DOI：
10.1093/pasj/psad016
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发表时间：
2023
影响因子：
2.3
通讯作者：
Uchiyama Hideki
中科院分区：
文献类型：
--
作者：
Yamamoto Kumiko;Yamauchi Shigeo;Nobukawa Masayoshi;Nobukawa Kumiko K;Uchiyama Hideki
银河脊X射线发射(GRXE)是位于银河系平面上的未分辨X射线发射，GRXE来自真正弥漫的等离子体还是未分辨的点源，目前仍存在争议。我们给出了用Suzaku对GRXE进行光谱分析的结果。为了考察点源起源，我们用活动双星(ABS)和非磁性激变变星(Non-MCV)混合的点源模型对1.2-10keV能带的GRXE谱进行了拟合，发现只要假设这些物种的标准金属丰度，该模型就不能代表GRXE谱的形状。特别是，标准丰度模型不能解释观测到的Si、S和Ar谱线以及以前报道的Fe谱线的强度。假设空间密度在太阳附近，ABS和非MCV的积分只占观测到的GRXE通量的30%。其他具有较强Si、S、Ar、Fe发射线的点源或弥散发射可以解释其余的原因。
The Galactic ridge X-ray emission (GRXE) is unresolved X-ray emission located on the Galactic plane, and whether the GRXE comes from truly diffuse plasma or unresolved point sources is still debatable. We present results of spectral analysis of the GRXE with Suzaku. In order to examine the point source origin, we fitted the GRXE spectra in the 1.2–10 keV energy band with a point source model, which is a mixture of active binary stars (ABs) and non-magnetic cataclysmic variables (non-mCVs), and found that the model cannot represent the GRXE spectral shape as long as the standard metal abundances of these species are assumed. In particular, the standard abundance model cannot account for the observed intensities of Si, S, and Ar lines as well as the previously reported Fe line. Assuming spatial densities in the solar neighborhood, integration of the ABs and non-mCVs accounts for only 30% of the observed GRXE flux. Other species of the point sources or diffuse emission with stronger Si, S, Ar, and Fe emission lines shall explain the rest.