AI 中文总结
研究在矮星系核区发现的光学瞬变源 AT2019ijn，其光学快速上升、缓慢衰减，射电异常明亮且有晚期峰值。核心方法是用离轴相对论喷流解释。主要贡献是代表新的相对论光学瞬变源，凸显射电巡天对发现离轴喷流事件的重要性。
AI 中文摘要
我们报告了在红移 z = 0.273 的矮星系核区发现的一个特殊光学瞬变源 AT2019ijn。它在 5 天内迅速升至光度 Mg = -21.1 的峰值，随后在一个多月内缓慢下降，在此期间光学辐射具有持续较高的黑体温度 T_BB~1.5 - 1.6×10^4 K。射电辐射异常，在光学发现后 640 天达到峰值，光度为 2×10^31 erg/s/Hz。其峰值射电光度比已知的射电明亮快速蓝色光学瞬变源和类似时期的超新星爆炸至少亮两个数量级，但与喷流潮汐瓦解事件相当。这种具有晚期峰值的明亮且持久的射电辐射可用视角约为 40 度的离轴相对论喷流来解释。我们讨论了 AT2019ijn 的可能起源，倾向于涉及约 10^5 Msun 中等质量黑洞的喷流潮汐瓦解事件，尽管喷流磁星模型不能完全排除。AT2019ijn 代表了一类新的相对论光学瞬变源，突出了射电巡天对于发现离轴喷流事件的重要性。
英文摘要
We report the discovery of a peculiar optical transient, AT2019ijn, occurred in the nuclear region of a dwarf galaxy at z=0.273. It rises rapidly to peak at a luminosity of Mg=-21.1 in 5 days, followed by a slow decline over more than a month, during which the optical emission has a persistently high blackbody temperature of T_BB~1.5-1.6x10^4 K. The radio emission is exceptional which peaks at 640 days after optical discovery with a high luminosity of 2x10^31 erg/s/Hz. The peak radio luminosity is at least two orders of magnitude brighter than known radio-bright fast blue optical transients and supernova explosions at similar epochs, but comparable to jetted tidal disruption events. The luminous and long-lasting radio emission with a late-time peak can be explained by an off-axis relativistic jet with a viewing angle of ~40 deg. We discuss possible origins for AT2019ijn and favor a jetted tidal disruption event involving an intermediate-mass black hole of ~10^5 Msun, although a jetted magnetar model cannot be fully ruled out. AT2019ijn represents a new class of relativistic optical transients that highlights the importance of radio surveys for discovering off-axis jetted events.
CommentsPublished in ApJ Letters
Journal refApJL, 1005, L49 (2026)
