AI 中文总结
本研究通过合成光变曲线模型与观测对比，揭示对不稳定超新星候选体SN 2018ibb的星周介质性质，发现其前身星在爆炸前经历短期质量损失增强。
AI 中文摘要
SN 2018ibb是迄今已确认的最佳对不稳定超新星（PISN）候选体之一。然而，其晚期光谱中出现了意外的蓝色通量超出，这可能源于超新星（SN）抛射物与致密星周介质（CSM）之间的相互作用。我们开发了与致密CSM相互作用的PISN合成光变曲线模型，并通过比较合成光变曲线与观测光变曲线来估算SN 2018ibb的CSM性质。我们发现，SN 2018ibb在峰值后150天起的辐射光度演化，可以很好地由与CSM的相互作用来重现，该CSM由质量损失率0.01(v_CSM/1,000 km/s) Msun/yr形成，其中v_CSM为CSM速度。在峰值后约300天观测到的光度转折表明，CSM相互作用在该时刻结束，致密CSM半径为8.5e16 cm。该CSM半径进而暗示，前身星在爆炸前经历了持续28/(v_CSM/1,000 km/s)年的增强质量损失。我们得出结论，PISN前身星可能在爆炸前几十年内经历短期质量损失增强，这与在核坍缩超新星前身星中经常观测到的情况相似。
英文摘要
SN 2018ibb is one of the best pair-instability supernova (PISN) candidates identified to date. It, however, showed unexpected blue flux excess in late-phase spectra, likely originating from the interaction between supernova (SN) ejecta and dense circumstellar matter (CSM). We develop synthetic light-curve models of PISNe interacting with dense CSM and estimate the CSM properties of SN 2018ibb by comparing the synthetic and observed light curves. We found that the bolometric luminosity evolution of SN 2018ibb from 150 d after the peak can be well reproduced by the interaction with the CSM formed by a mass-loss rate of 0.01(v_CSM/1,000 km/s) Msun/yr, where v_CSM is the CSM velocity. The observed luminosity break at around 300 d from the peak indicates that the CSM interaction ended at this time and the dense CSM radius was 8.5e16 cm. The CSM radius then implies that the mass loss of the progenitor was enhanced for 28/(v_CSM/1,000 km/s) yr before explosion. We conclude that PISN progenitors may experience short-term mass-loss enhancement within decades before explosion, similar to what is often observed in progenitors of core-collapse SNe.
Comments12 pages, 3 figures, accepted by Frontiers in Astronomy and Space Sciences
