论文标题
爆炸后2 - 3年，快速瞬态AT2018COW现场的热和发光来源
A hot and luminous source at the site of the fast transient AT2018cow at 2-3 years after its explosion
论文作者
论文摘要
我们在爆炸后，在Hubble Space望远镜（HST）拍摄的图像上，在快速蓝色光学瞬变（FBOT）AT2018COW的位置上发现了一个发光的延迟源后的位置。在紫外线和光学波长上都检测到该来源，并具有突出的H $α$排放。 It has a very stable brightness between the two epochs and a very blue spectral energy distribution (SED) consistent with $f_λ$ $\propto$ $λ^{-4.1 \pm 0.1}$, i.e. the Rayleigh-Jeans tail of a hot blackbody with a very high temperature of log($T$/K) $>$ 4.6 and luminosity of log($L$/$L_\odot$) $>$ 7.0。这个后期源不太可能是偶然对齐中无关的对象，或者由于AT2018COW的光回声。其他可能的情况在解释该晚期来源时也有一些困难，包括伴侣明星，恒星群，幸存的祖细胞星，与情节培养基（CSM），磁场或潮汐破坏事件中的延迟增生的相互作用（TDE）。长期和多波长监测将有助于解决其性质，并最终揭示“牛”的起源。
We report the discovery of a luminous late-time source at the position of the fast blue optical transient (FBOT) AT2018cow on images taken by the Hubble Space Telescope (HST) at 714 d and 1136 d after its explosion. This source is detected at both UV and optical wavelengths and has prominent H$α$ emission. It has a very stable brightness between the two epochs and a very blue spectral energy distribution (SED) consistent with $f_λ$ $\propto$ $λ^{-4.1 \pm 0.1}$, i.e. the Rayleigh-Jeans tail of a hot blackbody with a very high temperature of log($T$/K) $>$ 4.6 and luminosity of log($L$/$L_\odot$) $>$ 7.0. This late-time source is unlikely to be an unrelated object in chance alignment, or due to a light echo of AT2018cow. Other possible scenarios also have some difficulties in explaining this late-time source, including companion star(s), star cluster, the survived progenitor star, interaction with circumstellar medium (CSM), magnetar, or delayed accretion in a tidal disruption event (TDE). Long-term and multi-wavelength monitoring will help to resolve its nature and finally reveal the origin of the "Cow".
