In:
Symposium - International Astronomical Union, Cambridge University Press (CUP), Vol. 212 ( 2003), p. 395-403
Abstract:
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: ( i ) 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; ( ii ) because of enhanced α-rich freeze-out, 44 Ca, 48 Ti, and 64 Zn 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; and ( iii ) 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 M 82 may be attributed to hypernova explosions. We thus suggest that hypernovae make important contribution to the early Galactic (and cosmic) chemical evolution.
Type of Medium:
Online Resource
ISSN:
0074-1809
DOI:
10.1017/S0074180900212485
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
2003
SSG:
16,12
