论文标题
黄金的平移，但要找到氦气：从重力波跟踪观察结果发现超新星SN2019WXT
Panning for gold, but finding helium: discovery of the ultra-stripped supernova SN2019wxt from gravitational-wave follow-up observations
论文作者
论文摘要
我们介绍了在S191213G随访期间发现的瞬态的多波长观察结果，这是Ligo-Virgo协作报道的重力波（GW）事件，是低潜伏期搜索中可能的二进制中子星星合并。这次搜索产生了SN2019WXT，这是一个年轻的星系中的年轻瞬态，其天空位置（80 \％GW轮廓）和距离（$ \ sim $ 150 \，MPC）与GW事件的本地化不确定性合可能兼容。最初，瞬态的紧密约束年龄，相对较弱的峰值幅度（$ m_i \ sim -16.7 $ \，mag）和$ r- $ band的下降速度为$ \ sim 1 $ \，每5 \，天数似乎暗示着紧凑的二进制合并。然而，SN2019WXT在光谱上类似于IB型超新星，对光学 - 北红外进化的分析迅速得出了这样的结论：尽管它不能与S191213G相关，但它仍然代表了Stellar Evolution的极端结果。通过对光曲线进行建模，我们估计了$ \ sim 0.1 \，m_ \ odot $的弹出质量，其中包含$ \ sim 20 \％$的$^{56} $ ni。我们广泛地能够以氦和氧气为主导的组合物复制其光谱演化，并具有痕量的钙。我们考虑了各种祖细胞，这些祖细胞可能会引起SN2019WXT的观察到的特性，并得出结论，二元系统中的超脱衣舞起源是最有可能的解释。 Disentangling electromagnetic counterparts to GW events from transients such as SN2019wxt is challenging: in a bid to characterise the level of contamination, we estimated the rate of events with properties comparable to those of SN2019wxt and found that $\sim 1$ such event per week can occur within the typical GW localisation area of O4 alerts out to a luminosity distance of 500\,Mpc, beyond which it would become比当前电磁后续活动的典型深度淡淡。
We present the results from multi-wavelength observations of a transient discovered during the follow-up of S191213g, a gravitational wave (GW) event reported by the LIGO-Virgo Collaboration as a possible binary neutron star merger in a low latency search. This search yielded SN2019wxt, a young transient in a galaxy whose sky position (in the 80\% GW contour) and distance ($\sim$150\,Mpc) were plausibly compatible with the localisation uncertainty of the GW event. Initially, the transient's tightly constrained age, its relatively faint peak magnitude ($M_i \sim -16.7$\,mag) and the $r-$band decline rate of $\sim 1$\,mag per 5\,days appeared suggestive of a compact binary merger. However, SN2019wxt spectroscopically resembled a type Ib supernova, and analysis of the optical-near-infrared evolution rapidly led to the conclusion that while it could not be associated with S191213g, it nevertheless represented an extreme outcome of stellar evolution. By modelling the light curve, we estimated an ejecta mass of $\sim 0.1\,M_\odot$, with $^{56}$Ni comprising $\sim 20\%$ of this. We were broadly able to reproduce its spectral evolution with a composition dominated by helium and oxygen, with trace amounts of calcium. We considered various progenitors that could give rise to the observed properties of SN2019wxt, and concluded that an ultra-stripped origin in a binary system is the most likely explanation. Disentangling electromagnetic counterparts to GW events from transients such as SN2019wxt is challenging: in a bid to characterise the level of contamination, we estimated the rate of events with properties comparable to those of SN2019wxt and found that $\sim 1$ such event per week can occur within the typical GW localisation area of O4 alerts out to a luminosity distance of 500\,Mpc, beyond which it would become fainter than the typical depth of current electromagnetic follow-up campaigns.
