潮汐瓦解事件中的三次射电耀斑：喷流-风碰撞以及从AT2020vwl发现第三次射电耀斑
Triple radio flares from tidal disruption events: jet-wind collisions and the discovery of a third radio flare from AT2020vwl
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中文总结 AI 辅助
研究潮汐瓦解事件中射电耀斑，基于超爱丁顿风与喷流产生即时和延迟耀斑的框架，预测单个源会出现第三次耀斑。通过对AT2020vwl的长期监测发现第三次耀斑，还对另外两个TDEs的射电演化做了预测。
中文摘要 AI 辅助
潮汐瓦解事件（TDEs）的射电耀斑在两个不同时间尺度上被观测到：即时（在光学峰值附近）和延迟（光学峰值后数百到数千天）。最近提出的一个解释这种多样性的框架表明，超爱丁顿风产生即时耀斑，而在低吸积率下盘状态转变期间发射的喷流产生延迟耀斑。该框架的一个独特观测预测是，显示两种耀斑类型的单个源可能会出现第三次耀斑。当（较快的）喷流赶上（较慢的）风时，第三次耀斑就会发生。第三次耀斑的观测外观取决于系统参数。当两个激波前沿碰撞时，（较亮的）喷流会遇到密度变化，改变其同步辐射自吸收频率和观测通量。我们讨论了这种情况的观测外观，然后在对TDE AT2020vwl的新的长期监测射电观测中，展示了第三次射电耀斑的发现。这次耀斑与风-喷流框架中前两次耀斑的正向建模预测的两个激波前沿碰撞时间一致。我们对另外两个显示双射电耀斑的TDEs的长期射电演化进行了预测：ASASSN-15oi（可能显示弱耀斑或光变曲线变平）和AT2024tvd（预计即将经历第三次耀斑）。
英文摘要
Radio flares from tidal disruption events (TDEs) are observed on two distinct timescales: prompt (around the time of optical peak) and delayed (hundreds to thousands of days after optical peak). A recent framework put forward to explain this diversity suggests that super-Eddington winds produce prompt flares while jets launched during a disk state transition at low accretion rates produce delayed flares. A unique observational prediction of this framework is that individual sources showing both types of flares may be expected to show a third flare. This third flare will occur when the (faster) jet catches up with the (slower) wind. The observational appearance of the third flare depends on the system parameters. As the two shock fronts collide the (brighter) jet encounters a change in density, modifying its synchrotron-self-absorption frequency and observed flux. Here we discuss the observational appearance of such a scenario, and then show, in new long-term monitoring radio observations of the TDE AT2020vwl, the discovery of a third radio flare. This flare is coincident with the time at which forward modeling of the first two flares in a wind-jet framework predicts a collision between the two shock fronts. We make predictions for the long-term radio evolution of two other TDEs showing double radio flares: ASASSN-15oi (which may show a weak flare or flattening of the lightcurve) and AT2024tvd (which is predicted to imminently undergo a third flare).
