AI 中文总结
该研究通过XMM-Newton光谱发现准周期爆发源AT2019wzc的异常氮丰度，支持其为潮汐瓦解事件起源，相关气体或来自潮汐瓦解 debris stream自碰撞外流。
AI 中文摘要
准周期爆发（QPEs）是快速、重复出现的软X射线暴，其本质仍存在争议。在演化缓慢的光学暂现源AT2019wzc中已发现一个令人信服的QPE案例，可能与后主序恒星被超大质量黑洞的潮汐瓦解有关。进一步的潮汐瓦解事件（TDE）证据对理解AT2019wzc的本质、建立TDE与QPE的关联至关重要。本研究报告在XMM-Newton获取的高分辨率X射线光谱中检测到一条窄的蓝移N VI吸收线，而碳、氧等其他相似电离态元素的吸收线较弱或未检测到。该吸收线特征可由电离参数logξ~0.3 erg cm s⁻¹、柱密度N_H~10²⁰ cm⁻²的电离气体拟合，其氮丰度为太阳值的11.6⁺¹⁹.⁶₋₇.⁸倍。这种异常的氮丰度支持AT2019wzc起源于TDE，且吸收气体可能来自TDE debris stream自碰撞引发的外流。
英文摘要
Quasi-periodic eruptions (QPEs) are rapid, recurring soft X-ray bursts, whose nature is still in dispute. A compelling case of QPEs has emerged in the slowly evolving optical transient AT2019wzc, possibly associated with the tidal disruption of a post-main-sequence star by a supermassive black hole. Further evidence of a tidal disruption event (TDE) is crucial to understand the nature of AT2019wzc and establish the link between TDE and QPEs. Here we report the detection of a narrow, blueshifted N VI absorption line in its high-resolution X-ray spectra obtained by XMM-Newton, but weak or undetectable absorption lines from other elements of similar ionization states such as carbon and oxygen. The absorption line features can be reproduced by an ionized gas with ionization parameter $\log ξ\sim 0.3\ {\rm erg~cm~s^{-1}}$ and column density $N_{\rm H}\sim 10^{20}\ {\rm cm^{-2}}$, under the condition of a nitrogen abundance of $11.6_{-7.8}^{+19.6}$ times the solar value. This abnormal nitrogen abundance favors a TDE origin for AT2019wzc, and the absorbing gas may originate from the outflow induced by self-collision of the TDE's debris stream.
Comments8 pages, 4 figures, comments welcome
