http://arxiv.org/abs/1808.07580
Type IIb supernovae (SNe) are important candidates to understand mechanisms that drive the stripping of stripped-envelope (SE) supernova (SN) progenitors. While binary interactions and their high incidence are generally cited to favor them as Type IIb SN progenitors, this idea has not been tested using models covering a broad parameter space. In this paper we use single- and binary-star models at solar and low metallicities covering a broad parameter space to investigate the progenitors of and evolutionary pathways to Type IIb SNe. We find that single and binary stars contribute roughly the same as Type IIb SNe at solar metallicity. Binary stars only dominate as progenitors at low metallicity. We also find that our models can account for less than half the observationally inferred rate for Type IIb SNe at high metallicity, making up 4.5% of all core-collapse (CC) SNe. On the other hand, our models can account for the rates currently indicated by observations at low metallicity, making up 0.5-15% of all CC SNe. However, this requires low mass transfer efficiencies (~0.1) to prevent most progenitors from entering contact. We suggest that the stellar wind mass-loss rates at solar metallicity used in our models are too high. Lower mass-loss rates would widen the parameter space for binary Type IIb SNe at solar metallicity by allowing stars that initiate mass transfer earlier in their evolution to reach CC without getting fully stripped.
N. Sravan, P. Marchant and V. Kalogera
Fri, 24 Aug 18
14/45
Comments: Submitted to The Astrophysical Journal; Comments welcome