Maeda Keiichi, Kawabata Koji, Mazzali Paolo A, Tanaka Masaomi, Valenti Stefano, Nomoto Ken'ichi, Hattori Takashi, Deng Jinsong, Pian Elena, Taubenberger Stefan, Iye Masanori, Matheson Thomas, Filippenko Alexei V, Aoki Kentaro, Kosugi George, Ohyama Youichi, Sasaki Toshiyuki, Takata Tadafumi
Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, Kashiwa-no-ha 5-1-5, Kashiwa City, Chiba 277-8582, Japan.
Science. 2008 Feb 29;319(5867):1220-3. doi: 10.1126/science.1149437. Epub 2008 Jan 31.
Core-collapse supernovae (CC-SNe) are the explosions that announce the death of massive stars. Some CC-SNe are linked to long-duration gamma-ray bursts (GRBs) and are highly aspherical. One important question is to what extent asphericity is common to all CC-SNe. Here we present late-time spectra for a number of CC-SNe from stripped-envelope stars and use them to explore any asphericity generated in the inner part of the exploding star, near the site of collapse. A range of oxygen emission-line profiles is observed, including a high incidence of double-peaked profiles, a distinct signature of an aspherical explosion. Our results suggest that all CC-SNe from stripped-envelope stars are aspherical explosions and that SNe accompanied by GRBs exhibit the highest degree of asphericity.
核心坍缩超新星（CC-SNe）是宣告大质量恒星死亡的爆炸。一些CC-SNe与长持续时间伽马射线暴（GRBs）相关联，并且具有高度的非球对称性。一个重要的问题是，非球对称性在所有CC-SNe中普遍到何种程度。在这里，我们展示了来自剥离包层恒星的一些CC-SNe的晚期光谱，并利用它们来探索在爆炸恒星内部靠近坍缩部位产生的任何非球对称性。观测到了一系列氧发射线轮廓，包括双峰轮廓的高发生率，这是一种非球对称爆炸的明显特征。我们的结果表明，所有来自剥离包层恒星的CC-SNe都是非球对称爆炸，并且伴有GRBs的超新星表现出最高程度的非球对称性。
