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arXiv 2205.05097astro-ph.HE
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环界核瞬变AT2019pev的X射线观测

An X-ray View of the Ambiguous Nuclear Transient AT2019pev

Zhefu Yu, C. S. Kochanek, S. Mathur, K. Auchettl, D. Grupe, T. W. -S. Holoien

摘要:

AT 2019 pev是位于$z=0.096$的窄线塞弗特1星系中的一个核瞬变。档案紫外线,光学和红外线数据显示潮汐破裂事件(TDE)和活动星系核(AGN)的特征,其性质尚未完全了解。我们提出了详细的X射线观测AT 2019pev采取雨燕,钱德拉和NICER超过173天的演变,因为第一个雨燕XRT时代。X射线亮度在第一个Swift XRT纪元到光变曲线峰值的五天内增加了五倍。光变曲线在$\sim$ 75天内衰减10倍,然后在后期以微弱的再增亮趋势衰减。X射线谱在峰前呈现出“亮时硬”的趋势,峰后呈现出“暗时硬”的趋势,这可能表明吸积态发生了转变。档案地基光学观测显示类似的时间演变的X射线光变曲线。在地面观测的季节限制之外,盖亚的光变曲线在光学发现后223天正朝着同样明亮或更明亮的峰值上升。结合我们的X射线分析和档案多波长数据,AT 2019 pev更接近于活动星系核瞬态。

英文摘要:

AT2019pev is a nuclear transient in a narrow-line Seyfert 1 galaxy at $z=0.096$. The archival ultraviolet, optical and infrared data showed features of both tidal disruption events (TDEs) and active galactic nuclei (AGNs), and its nature is not fully understood. We present detailed X-ray observations of AT2019pev taken with Swift, Chandra and NICER over 173 days of its evolution since the first Swift XRT epoch. The X-ray luminosity increases by a factor of five in five days from the first Swift XRT epoch to the lightcurve peak. The lightcurve decays by a factor of ten over $\sim$75 days and then flattens with a weak re-brightening trend at late times. The X-ray spectra show a "harder-when-brighter" trend before peak and a "harder-when-fainter" trend after peak, which may indicate a transition of accretion states. The archival ground-based optical observations show similar time evolution as the X-ray lightcurves. Beyond the seasonal limit of the ground-based observations, the Gaia lightcurve is rising toward an equally bright or brighter peak 223 days after the optical discovery. Combining our X-ray analysis and archival multi-wavelength data, AT2019pev more closely resembles an AGN transient.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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