Evidence of a Massive Stellar Disruption in the X-Ray Spectrum of ASASSN-14li
Evidence of a Massive Stellar Disruption in the X-Ray Spectrum of ASASSN-14li
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DOI：
10.3847/2041-8213/ace03c
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发表时间：
2023-08
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影响因子：
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通讯作者：
Jonathan M. Miller;B. Mockler;E. Ramirez-Ruiz;P. Draghis;J. Drake;J. Raymond;M. Reynolds;Xin Xiang;Sol Bin Yun;A. Zoghbi
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文献类型：
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作者：
Jonathan M. Miller;B. Mockler;E. Ramirez-Ruiz;P. Draghis;J. Drake;J. Raymond;M. Reynolds;Xin Xiang;Sol Bin Yun;A. Zoghbi
ASASSN-14 li潮汐扰动事件的接近和持续时间导致了X射线和紫外线中狭窄的蓝移吸收线的发现。在X射线吸收中看到的气体与靠近椭圆轨道远心的束缚物质一致，或者与塞弗特-1活动星系核中看到的盘风相似。本文对ASASSN-14 li的最深高分辨率XMM-牛顿谱和钱德拉谱进行了新的分析。受类He和类H电荷态的相对强度驱动，数据要求[N/C] ≥ 2.4，与UV光谱结果定性一致。在TDE的模拟中，ASASSN-14 li的X射线光谱中所看到的那种流动并没有被清楚地预测出来;这使得观察到的吸收可能与之前活动星系核（AGN）活动中释放的气体有关。然而，在这个分析中揭示的丰度模式指向一个单一的星星，而不是一个标准的活动星系核吸积流组成的无数气体的贡献。对这些数据最简单的解释可能是，一颗中等质量的星星（M 3 M）具有显著的CNO加工被破坏了。另一种解释是，一颗质量较低的星星被破坏了，它以前被剥离了它的外壳。我们讨论了我们的分析和这些解释的优势和局限性。
The proximity and duration of the tidal disruption event ASASSN-14li led to the discovery of narrow, blueshifted absorption lines in X-rays and UV. The gas seen in X-ray absorption is consistent with bound material close to the apocenter of elliptical orbital paths, or with a disk wind similar to those seen in Seyfert-1 active galactic nuclei. We present a new analysis of the deepest high-resolution XMM-Newton and Chandra spectra of ASASSN-14li. Driven by the relative strengths of He-like and H-like charge states, the data require [N/C] ≥ 2.4, in qualitative agreement with UV spectral results. Flows of the kind seen in the X-ray spectrum of ASASSN-14li were not clearly predicted in simulations of TDEs; this left open the possibility that the observed absorption might be tied to gas released in prior active galactic nucleus (AGN) activity. However, the abundance pattern revealed in this analysis points to a single star rather than a standard AGN accretion flow comprised of myriad gas contributions. The simplest explanation of the data is likely that a moderately massive star (M ≳ 3 M ⊙) with significant CNO processing was disrupted. An alternative explanation is that a lower mass star was disrupted that had previously been stripped of its envelope. We discuss the strengths and limitations of our analysis and these interpretations.