X-ray spectroscopy of the accretion disk corona source 2S 0921-630 with Suzaku archival data
X-ray spectroscopy of the accretion disk corona source 2S 0921-630 with Suzaku archival data
复制标题
吸积盘日冕源 2S 0921-630 的 X 射线光谱与朱雀档案数据
DOI：
10.1093/pasj/psac086
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Tadayasu
中科院分区：
文献类型：
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作者：
Yoneyama;Tomokage;Dotani;Tadayasu
2S 0921−630是一颗低质量X射线双星（LMXB），其轨道周期为2.9 d。过去的X射线观测显示，2S 0921−630有一个扩展的吸积盘日冕（ADC），系统的大部分X射线都是从这里发射的。我们报告了2S 0921−630的朱雀档案数据分析结果。平均X射线光谱是用黑体辐射（kTbb <$0.3 keV）复制的，黑体辐射被温度为1.2 keV的光学厚气体（“康普顿云”;光学深度τ <$21）康普顿化，并结合了13条发射线。我们发现，大部分的发射线对应于高度电离的原子：O，Ne，Mg，Si，S，Ar和Fe。还探测到半中性铁（Fe textsci-textscxvii）的Kα发射线和吸收边。半中性铁的Kα线非常宽，σ宽为0.11 ± 0.02 keV，对应于开普勒运动在半径为109 cm处的多普勒展宽。我们认为观测到的半中性铁线起源于康普顿云外部吸积盘的内部，即，康普顿云的半径可能是109厘米。
2S 0921−630 is an eclipsing low-mass X-ray binary (LMXB) with an orbital period of ∼9 d. Past X-ray observations have revealed that 2S 0921−630 has an extended accretion disk corona (ADC), from which most of the X-rays from the system are emitted. We report the result of our Suzaku archival data analysis of 2S 0921−630. The average X-ray spectrum is reproduced with a blackbody emission (kTbb∼ 0.3 keV) Comptonized by optically thick gas (“Compton cloud”; optical depth τ ∼ 21) with a temperature of ∼2 keV, combined with 13 emission lines. We find that most of the emission lines correspond to highly ionized atoms: O, Ne, Mg, Si, S, Ar, and Fe. A Kα emission line and an absorption edge of semi-neutral iron (Fe textsci– textscxvii) are also detected. The semi-neutral iron Kα line is significantly broad, with a width of 0.11 ± 0.02 keV in sigma, which corresponds to the Doppler broadening by the Kepler motion at a radius of ∼109cm. We suggest that the observed semi-neutral iron line originates at the inner part of the accretion disk in the immediate outside of the Compton cloud, i.e., the Compton cloud may have a radius of ∼109cm.