论文标题
在2020wey和一类微弱而快速的潮汐破坏事件
AT 2020wey and the class of faint and fast Tidal Disruption Events
论文作者
论文摘要
我们介绍了2020wey的光学和紫外线特性的分析，该特性是124.3 MPC的微弱而快速的潮汐破坏事件（TDE）。物体的光曲线以$ m_ {g} = -17.45 $ mag的绝对幅度达到顶峰，最大降压光度为$ l _ {\ rm peak} =（8.74 \ pm0.69）\ times10^{42} $ erg s $^{42} $ 日期。从上一次非检测到$ g $ -band峰的时间为22.94 $ \ pm $ 2.03天，上升由$ l \ propto t^{1.8} $很好地描述。降低了降低光曲线的衰落，它比规范$ t^{ - 5/3} $ power Law的尖锐指数衰减更陡峭，在2020wey降低了迄今为止最快的TDE。多波长适合光曲线，这表明$ m _*= 0.11m _ {\ odot} $的星形完全破坏了$ m _ {\ rm bh}的黑洞= 10^{6.46} m _ {\ odot} $。我们的光谱数据集揭示了广泛的（$ \ sim10^{4} $ km s $ s $^{ - 1} $）balmer和He II $λ$ 4686行，H $α$达到了峰值，而$ \\ sim8.2 $，而与持续动力相比，lag lag lag lag。与以前的微弱和快速的TDE相反，在2020wey的光谱中没有明显的Bowen荧光线。 MOSFIT衍生的TDE的黑洞质量与其下降率之间存在很强的相关性。但是，在2020年，这种相关性是一个离群值，这可能表明其快速下降可能取决于与后备不同的物理机制。在对2018年至2020年之间观察到的30个TDE的样本进行体积校正后，我们得出结论，微弱的TDE本质上并不罕见，它们应构成$ \ sim $ 50-60％的整个人群的$ 50-60％，它们的数量可以减轻观察到的TDE TDE利率估算值之间的某些张力。我们计算光学TDE光度函数，并找到陡峭的幂律关系$ dn/dl_ {g} \ propto {l_ {g}}}^{ - 2.36} $。
We present an analysis of the optical and UV properties of AT 2020wey, a faint and fast tidal disruption event (TDE) at 124.3 Mpc. The light curve of the object peaked at an absolute magnitude of $M_{g} = -17.45$ mag and a maximum bolometric luminosity of $L_{\rm peak}=(8.74\pm0.69)\times10^{42}$ erg s$^{-1}$, making it comparably faint with iPTF16fnl, the faintest TDE to date. The time from the last non-detection to the $g$-band peak is 22.94 $\pm$ 2.03 days and the rise is well described by $L\propto t^{1.8}$. The decline of the bolometric light curve is described by a sharp exponential decay steeper than the canonical $t^{-5/3}$ power law, making AT 2020wey the fastest declining TDE to date. Multi-wavelength fits to the light curve indicate a complete disruption of a star of $M_*=0.11M_{\odot}$ by a black hole of $M_{\rm BH}=10^{6.46}M_{\odot}$. Our spectroscopic dataset reveals broad ($\sim10^{4}$ km s$^{-1}$) Balmer and He II $λ$4686 lines, with H$α$ reaching its peak with a lag of $\sim8.2$ days compared to the continuum. In contrast to previous faint and fast TDEs, there are no obvious Bowen fluorescence lines in the spectra of AT 2020wey. There is a strong correlation between the MOSFIT-derived black hole masses of TDEs and their decline rate. However, AT 2020wey is an outlier in this correlation, which could indicate that its fast early decline may be dictated by a different physical mechanism than fallback. After performing a volumetric correction to a sample of 30 TDEs observed between 2018 and 2020, we conclude that faint TDEs are not rare by nature and that they should constitute up to $\sim$ 50 - 60 % of the entire population and their numbers could alleviate some of the tension between the observed and theoretical TDE rate estimates. We calculate the optical TDE luminosity function and we find a steep power-law relation $dN/dL_{g} \propto {L_{g}}^{-2.36}$.
