论文标题
Asassn-14KO是ESO 253-G003中的定期核瞬变
ASASSN-14ko is a Periodic Nuclear Transient in ESO 253-G003
论文作者
论文摘要
我们提出了这样的发现，即Asassn-14Ko是Galaxy ESO 253-G003中心的定期燃烧的AGN。在全天空自动化的超新星（ASAS-SN）发现时，它被归类为靠近核的超新星。随后的V-和G波段ASAS-SN观察的六年表明，Asassn-14KO具有定期发生的核耀斑。 17个观察到的爆发显示了随着时间的变化的证据，平均周期为$ p_0 = 114.2 \ pm 0.4 $ 0.4 $天和$ \ dot {p} = -0.0017 \ pm0.0003 $的周期衍生物。 2020年5月发生的最新爆发是按照预期进行的，在上升过程中表现出光谱变化，A具有明亮的黑体光谱能量分布，类似于潮汐破坏事件（TDES）。 X射线通量在爆发开始时降低了4倍，然后在约8天后恢复到其静止通量。苔丝观察到在4-6部门的爆发中爆发，显示光学的上升时间为5.60 \ pm 0.05美元，并且最适合指数模型的下降时间。我们讨论了几种可能解释Asassn-14Ko定期爆发的情况，但目前赞成反复的部分TDE。下一次爆发应在UT 2020-09-7.4 $ \ pm $ 1.1和UT 2020-12-26.5 $ \ pm $ 1.4的光学上达到顶峰。
We present the discovery that ASASSN-14ko is a periodically flaring AGN at the center of the galaxy ESO 253-G003. At the time of its discovery by the All-Sky Automated Survey for Supernovae (ASAS-SN), it was classified as a supernova close to the nucleus. The subsequent six years of V- and g-band ASAS-SN observations reveal that ASASSN-14ko has nuclear flares occurring at regular intervals. The seventeen observed outbursts show evidence of a decreasing period over time, with a mean period of $P_0 = 114.2 \pm 0.4$ days and a period derivative of $\dot{P} = -0.0017\pm0.0003$. The most recent outburst in May 2020, which took place as predicted, exhibited spectroscopic changes during the rise and a had a UV bright, blackbody spectral energy distribution similar to tidal disruption events (TDEs). The X-ray flux decreased by a factor of 4 at the beginning of the outburst and then returned to its quiescent flux after ~8 days. TESS observed an outburst during Sectors 4-6, revealing a rise time of $5.60 \pm 0.05$ days in the optical and a decline that is best fit with an exponential model. We discuss several possible scenarios to explain ASASSN-14ko's periodic outbursts, but currently favor a repeated partial TDE. The next outbursts should peak in the optical on UT 2020-09-7.4$ \pm $1.1 and UT 2020-12-26.5$ \pm $1.4.
