论文标题
在2019AZH的潮汐破坏事件中，可能过渡到积聚状态后的过渡状态后，迟到的无线电耀斑
A Late-Time Radio Flare following a Possible Transition in Accretion State in the Tidal Disruption Event AT 2019azh
论文作者
论文摘要
我们在此报告2019AZH的光学潮汐破坏事件（TDE）的无线电随访观察结果。先前报道的对该TDE的X射线观察结果显示，在光学发现后约8个月，大约8个月，较早的X射线观测在早期的变异性和显着增加的发光度增加了$ \ sim 10 $。 X射线发射主要由中间硬X射线主导，并且在X射线峰周围非常柔软，即$ L_X \ SIM 10^{43} {43} \ rm \，Erg \，s^{ - 1} $。此处报道的高节奏$ 15.5 $ GHz的观察结果表明，无线电发射的提前增长，随后是恒定的光曲线和延迟的耀斑。这种耀斑大约在观察到的X射线峰值光度时开始，并在X射线峰值之后和光学发现后一年达到峰值。无线电耀斑在$νl_ν\ sim 10^{38} \ rm \，erg \，s^{ - 1} $上峰值，比耀斑之前的发射高两个。鉴于晚期无线电和X射线耀斑以及X射线光谱的演变，我们推测了该TDE的吸积状态下可能的过渡，类似于黑洞X射线二进制文件中观察到的行为。我们将2019AZH的无线电性能与其他已知的TDE进行了比较，并专注于与TDE Asassn-15OI的后期无线电耀斑的相似之处。
We report here radio follow-up observations of the optical Tidal Disruption Event (TDE) AT 2019azh. Previously reported X-ray observations of this TDE showed variability at early times and a dramatic increase in luminosity, by a factor of $\sim 10$, about 8 months after optical discovery. The X-ray emission is mainly dominated by intermediate hard--soft X-rays and is exceptionally soft around the X-ray peak, which is $L_X \sim 10^{43} \rm \, erg \, s^{-1}$. The high cadence $15.5$ GHz observations reported here show an early rise in radio emission followed by an approximately constant light curve, and a late-time flare. This flare starts roughly at the time of the observed X-ray peak luminosity and reaches its peak about $110$ days after the peak in the X-ray, and a year after optical discovery. The radio flare peaks at $νL_ν \sim 10^{38} \rm \, erg \, s^{-1}$, a factor of two higher than the emission preceding the flare. In light of the late-time radio and X-ray flares, and the X-ray spectral evolution, we speculate a possible transition in the accretion state of this TDE, similar to the observed behavior in black hole X-ray binaries. We compare the radio properties of AT 2019azh to other known TDEs, and focus on the similarities to the late time radio flare of the TDE ASASSN-15oi.
