Massive star evolution and nucleosynthesis: Lower end of Fe-core-collapse supernova progenitors and remnant neutron star mass distribution

In order to explore various aspects of stellar evolution, supernovae, gamma ray bursts, and nucleosynthesis, we have developed a new efficient stellar evolution code. In this paper, we describe this new code and compare the results with those calculated by the previous code. Specifically, we focus on the progenitor evolution of the lower end of Fe-core-collapse supernovae, and the mass distribution of remnant neutron stars. We describe how different assumptions will lead to different neutron star mass distributions. We also review some of the recent work by our research group.