论文标题
HSC-SSP瞬态调查：正常型超新星的早期光度法和上升时间的影响
The HSC-SSP Transient Survey: Implications from Early Photometry and Rise Time of Normal Type Ia Supernovae
论文作者
论文摘要
由于在爆炸发生后的几天内发现了繁荣的IA型超新星（SNE IA），因此已经证实了早期阶段表现出亮度过高的SNE IA（早期sne sne ia）。在本文中，我们通过半年瞬态调查（HSCRIME-CAM SUBARU策略计划（HSC SSP）的一部分，在COSMOS场上报告了七个具有光学上正常的SNE IA（六个早期检测和1个深度未检测极限）的早期相 - 观察结果。特别是，在发现后的前四天，发现了HSC17BMHK的HSC17BMHK的蓝色光曲线过量。光波长中的蓝色早期过量不仅可以通过与非脱位伴侣或周围密集的杂质物质的相互作用来解释，而且还可以通过$^{56} $ ni在Sn ejecta表面的放射性衰减提供动力。 Given the growing evidence of the early-excess discoveries in normal SNe Ia that have longer rise times than the average and a similarity in the nature of the blue excess to a luminous SN Ia subclass, we infer that early excess discovered in HSC17bmhk and other normal SNe Ia are most likely attributed to radioactive $^{56}$Ni decay at the surface of the SN ejecta.为了成功识别与HSC17BMHK相似的早期过量的正常SNE IA，需要早期的紫外线光学法术或高环境蓝波段调查。
With a booming number of Type Ia supernovae (SNe Ia) discovered within a few days of their explosions, a fraction of SNe Ia that show luminosity excess in the early phase (early-excess SNe Ia) have been confirmed. In this article, we report early-phase observations of seven photometrically normal SNe Ia (six early detections and one deep non-detection limit) at the COSMOS field through a half-year transient survey as a part of the Hyper Suprime-Cam Subaru Strategic Program (HSC SSP). In particular, a blue light-curve excess was discovered for HSC17bmhk, a normal SN Ia with rise time longer than 18.8 days, during the first four days after the discovery. The blue early excess in optical wavelength can be explained not only by interactions with a non-degenerate companion or surrounding dense circumstellar matter but also radiation powered by radioactive decays of $^{56}$Ni at the surface of the SN ejecta. Given the growing evidence of the early-excess discoveries in normal SNe Ia that have longer rise times than the average and a similarity in the nature of the blue excess to a luminous SN Ia subclass, we infer that early excess discovered in HSC17bmhk and other normal SNe Ia are most likely attributed to radioactive $^{56}$Ni decay at the surface of the SN ejecta. In order to successfully identify normal SNe Ia with early excess similar to that of HSC17bmhk, early UV photometries or high-cadence blue-band surveys are necessary.
