论文标题
钙丰富的瞬时SN 2019EHK的晚期观察显示纯放射性衰减电源
Late-time Observations of Calcium-Rich Transient SN 2019ehk Reveal a Pure Radioactive Decay Power Source
论文作者
论文摘要
我们介绍$ \ textit {Hubble Space望远镜} $成像富含钙的Supernova（SN）2019EHK在爆炸后276-389天。这些观察结果代表了迄今为止富含钙的瞬态的最新光度测量值，并允许第一个机会分析该观察性SN类中对象的晚期演变。我们发现，SN 2019EHK的后期降压光曲线可以通过$ {}^{56} {56} \ textrm {co} $的放射性衰减来描述，我们得出质量为$ m（{}}^{56}}^{56} \ textrm {co} {co} {co}） 10^{ - 2} $$ \ rm {m} _ \ odot $。此外，辐射光度的下降速度需要在时间尺度上泄漏$γ$ - rays $t_γ= 53.9 \ pm 1.30 $天，但我们没有发现SN extea中不完整的正电子诱捕的统计证据。尽管我们的观察结果不能限制SN 2019EHK合成的其他放射性同位素的确切质量，但我们估计质量比极限为$ m（{}^{57} \ textrm {co}） / m（{}^{}^{56}} {56}^{56} \ textrm {co} {co} {co}）\ leq 0.030 $。该极限与低质量白色矮人合并中产生的爆炸性核合成一致，这是SN 2019EHK早期研究中最喜欢的祖细胞场景之一。
We present $\textit{Hubble Space Telescope}$ imaging of the Calcium-rich supernova (SN) 2019ehk at 276 - 389 days after explosion. These observations represent the latest photometric measurements of a Calcium-rich transient to date and allows for the first opportunity to analyze the late-time evolution of an object in this observational SN class. We find that the late-time bolometric light curve of SN 2019ehk can be described predominantly through the radioactive decay of ${}^{56}\textrm{Co}$ for which we derive a mass of $M({}^{56}\textrm{Co}) = (2.8 \pm 0.1) \times 10^{-2}$$\rm{M}_\odot$. Furthermore, the rate of decline in bolometric luminosity requires the leakage of $γ$-rays on timescale $t_γ = 53.9 \pm 1.30$ days, but we find no statistical evidence for incomplete positron trapping in the SN ejecta. While our observations cannot constrain the exact masses of other radioactive isotopes synthesized in SN 2019ehk, we estimate a mass ratio limit of $M({}^{57}\textrm{Co}) / M({}^{56}\textrm{Co}) \leq 0.030$. This limit is consistent with the explosive nucleosynthesis produced in the merger of low-mass white dwarfs, which is one of the favored progenitor scenarios in early-time studies of SN 2019ehk.
