2002/09/04 by Ken'ichi Nomoto, Nomoto, Ken'ichi, Keiichi Maeda +9
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0209064
Invited talk at IAU Symposium 212, "A Massive Star Odyssey, from Main Sequence to Supernova", to be published in the Proceedings (San Francisco: ASP) eds. K.A. van der Hucht, A. Herrero, & C. Esteban, 9 pages
arxiv created 2002/09/04 · arxiv updated 2009/12/01
We review the characteristics of nucleosynthesis in 'Hypernovae', i.e., core-collapse supernovae with very large explosion energies ( \gsim 1052 ergs). The hypernova yields show the following characteristics: 1) The mass ratio between the complete and incomplete Si burning regions is larger in hypernovae than normal supernovae. As a result, higher energy explosions tend to produce larger [(Zn, Co, V)/Fe] and smaller [(Mn, Cr)/Fe], which could explain the trend observed in very metal-poor stars. 2) Because of enhanced α-rich freezeout, 44Ca, 48Ti, and 64Zn are produced more abundantly than in normal supernovae. The large [(Ti, Zn)/Fe] ratios observed in very metal poor stars strongly suggest a significant contribution of hypernovae. 3) Oxygen burning takes place in more extended regions in hypernovae to synthesize a larger amount of Si, S, Ar, and Ca ("Si"), which makes the "Si"/O ratio larger. The abundance pattern of the starburst galaxy M82 may be attributed to hypernova explosions. We thus suggest that hypernovae make important contribution to the early Galactic (and cosmic) chemical evolution.