论文标题
2018HYZ II的潮汐破坏事件：部分破坏的恒星的光曲线建模
The Tidal Disruption Event AT 2018hyz II: Light Curve Modeling of a Partially Disrupted Star
论文作者
论文摘要
在2018hyz（= Asassn-18zj）上是一个潮汐破坏事件（TDE），位于静态E+A星系核中，$ z = 0.04573 $，首先由全天自动化的SupperMated Survey（ASAS-SN）检测到。我们提出了瞬态的光学+UV光度法，以及X射线频谱和无线电上限。 AT 2018HYZ的侧侧光曲线与其他已知的TDE相当，并以$ t^{ - 5/3} $在早期时的速度下降，并在$ t { - 5/3} $上降低，发出了$ e = 9 \ times10^{50} $ erg的总辐射能量。射线峰后约50天，在紫外线曲线中出现了多余的凸起，然后将其扁平超过250天。光曲线在液压峰后约50天持续至少100天的紫外线显示出多余的凸起，这可能与流出有关。我们检测到存在至少86天的常数X射线源。 X射线频谱显示了$ \ sim 4 \ sim 4 \ times10^{ - 14} $ erg cm $^{ - 2} $ s $ s $^{ - 1} $的总未吸收通量，并且最适合Blackbody Plus Powerlaw模型，具有$γ= 0.8 $的光子指数。热X射线模型无法解释光子$> 1 $ keV，而无线电非检测偏爱反向弹药散射，而不是用于非热组件的喷气机。 We model the optical and UV light curves using the Modular Open-Source Fitter for Transients (MOSFiT) and find a best fit for a black hole of $5.2\times10^6$ M$_\odot$ partially disrupting a $0.1$ M$_\odot$ star (stripping a mass of $\sim 0.01$ M$_\odot$ for the inferred impact parameter, $β=0.6$).小碎片质量所隐含的低光学深度可能解释了我们如何在2018年hyz的光谱中看到具有磁盘样线图的氢发射（请参阅我们的同伴论文，Short等人，Short等人〜2020）。
AT 2018hyz (=ASASSN-18zj) is a tidal disruption event (TDE) located in the nucleus of a quiescent E+A galaxy at a redshift of $z = 0.04573$, first detected by the All-Sky Automated Survey for Supernovae (ASAS-SN). We present optical+UV photometry of the transient, as well as an X-ray spectrum and radio upper limits. The bolometric light curve of AT 2018hyz is comparable to other known TDEs and declines at a rate consistent with a $t^{-5/3}$ at early times, emitting a total radiated energy of $E = 9\times10^{50}$ erg. An excess bump appears in the UV light curve about 50 days after bolometric peak, followed by a flattening beyond 250 days. The light curve shows an excess bump in the UV about 50 days after bolometric peak lasting for at least 100 days, which may be related to an outflow. We detect a constant X-ray source present for at least 86 days. The X-ray spectrum shows a total unabsorbed flux of $\sim 4\times10^{-14}$ erg cm$^{-2}$ s$^{-1}$ and is best fit by a blackbody plus power-law model with a photon index of $Γ= 0.8$. A thermal X-ray model is unable to account for photons $> 1$ keV, while the radio non-detection favors inverse-Compton scattering rather than a jet for the non-thermal component. We model the optical and UV light curves using the Modular Open-Source Fitter for Transients (MOSFiT) and find a best fit for a black hole of $5.2\times10^6$ M$_\odot$ partially disrupting a $0.1$ M$_\odot$ star (stripping a mass of $\sim 0.01$ M$_\odot$ for the inferred impact parameter, $β=0.6$). The low optical depth implied by the small debris mass may explain how we are able to see hydrogen emission with disk-like line profiles in the spectra of AT 2018hyz (see our companion paper, Short et al.~2020).
