Hypernovae and their Nucleosynthesis [article]

Ken'ichi Nomoto, Keiichi Maeda, Hideyuki Umeda, Takuya Ohkubo, Jingsong Deng, Paolo Mazzali
2002 arXiv   pre-print
We review the characteristics of nucleosynthesis in 'Hypernovae', i.e., core-collapse supernovae with very large explosion energies ( 10^52 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)
more » ... cause 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.
arXiv:astro-ph/0209064v1 fatcat:utcwylg6d5fmtlaiwr6fj55p6u