SN2018ibb is a recently observed hydrogen-poor superluminous supernova that appears to be powered by the decay of 30 M _⊙ of radioactive nickel. This supernova has been suggested to show hybrid signatures of a pair-instability supernova and an interacting supernova. In a previous paper, we found that rotating, metal-enriched pair-instability supernova progenitors appeared to check both of these boxes. In this paper, we model the lightcurves of the pair-instability supernovae using STELLA. We find that the STELLA models can explain the overall shape of the bolometric lightcurve of SN2018ibb, though not specific morphological features such as the luminosity peak or the bump at roughly 300 days after the peak. We also estimate the contribution from interaction and find that with relatively low wind velocities, the circumstellar medium originating from the stellar winds is consistent with the evidence for interaction in the spectra. The observed values of the photosphere velocity in the 100 days after peak luminosity are similar to the STELLA models, but the deceleration is lower. This leads to the biggest inconsistency, which is the blackbody temperature of SN2018ibb being much hotter than any of the STELLA models. We note that this high temperature (and the flat velocity) may be difficult to reconcile with the long rise time of SN2018ibb, but nevertheless conclude that if it is accurate, this discrepancy represents a challenge for SN2018ibb being a robust PISN candidate. This result is noteworthy given the lack of other scenarios for this supernova.

中文翻译：

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SN2018ibb背景下高能对不稳定超新星的STELLA光曲线


SN2018ibb 是最近观测到的一颗贫氢超发光超新星，似乎由 30 的衰变提供动力中号_⊙放射性镍。这颗超新星被认为显示出一对不稳定超新星和相互作用超新星的混合特征。在之前的一篇论文中，我们发现旋转的、富含金属的对不稳定超新星前身似乎满足了这两个条件。在本文中，我们使用 STELLA 对不稳定超新星的光曲线进行建模。我们发现 STELLA 模型可以解释 SN2018ibb 的辐射热光曲线的整体形状，但不能解释特定的形态特征，例如光度峰值或峰值后大约 300 天的凹凸。我们还估计了相互作用的贡献，发现在风速相对较低的情况下，源自恒星风的星周介质与光谱中相互作用的证据是一致的。光度峰值后100天的光球速度观测值与STELLA模型相似，但减速度较小。这导致了最大的不一致，即 SN2018ibb 的黑体温度比任何 STELLA 模型都要热得多。我们注意到这种高温（和平坦速度）可能很难与 SN2018ibb 的长上升时间相一致，但尽管如此，我们得出的结论是，如果准确的话，这种差异对 SN2018ibb 作为强大的 PISN 候选者来说是一个挑战。鉴于这颗超新星缺乏其他场景，这一结果值得注意。