|Speaker:||Koh Takahashi (U. Tokyo)|
|Title:||Evolution of the most massive asymptotic giant branch star as a progenitor for electron capture supernovae|
|Date (JST):||Thu, Jul 04, 2013, 14:00 - 15:00|
|Place:||Seminar Room A|
The most massive asymptotic giant branch (AGB) star can form a critical mass ONe core at its center and core collapse of such a critical ONe core ends up as an electron capture supernova (ECSN). In this talk, I will present evolutionary properties of the most massive AGB star as a progenitor system of ECSNe.
The model of ECSNe has plenty of important suggestions on both observation and theory. Explosion properties which can be inferred by considering the pre-explosion structure of an AGB star provide a possible explanation for some low-energetic supernovae (e.g. SN2005cs)and also a part of type IIn supernovae (e.g. SN2008S). Several authors discuss that the Crab supernova, SN1054, can be a likely candidate of ECSN as well. As for theory,ECSN model is the only exception for which a one dimensional simulation can model a successful explosion a priori. However, there had been only one evolutionary calculation for ECSN, done by Nomoto in 1987, and thus a modern progenitor calculation as a basis of theoretical investigation is strongly demanded.
Recently, we have accomplished a progenitor calculation for ECSN for the first time in twenty six years and updated a pre-explosion structure of the model. Evolutionary sequences for this massive AGB star, which is located at the boundary region of massive stars and intermediate-mass stars, stand out from usual massive or intermediate-mass stellar evolution. I will discuss how characteristics of the progenitor evolution can be understood and what physics are needed to model for a plausible structure of ECSN progenitor.