The Chemical Yields of Stars in the Mass Range 9–15 <i>M</i> <sub>⊙</sub>
Marco Limongi, Lorenzo Roberti, Agnese Falla, A. Chieffi, K. Nomoto
Abstract
Abstract In M. Limongi et al. we presented and discussed the main evolutionary properties and final fate of stars in the mass range 7−15 M ⊙ . The evolutions of those models were computed by means of a medium-sized nuclear network that guaranteed a proper calculation of the nuclear energy generation and hence a good modeling of the physical evolution of these stars. In the present paper, we extend this study by computing the detailed chemical yields of stars in the mass range 9−15 M ⊙ , i.e., those stars that explode as core-collapse supernovae. The explosive nucleosynthesis is then computed in the framework of the thermal bomb–induced explosion by means of the HYPERION code. We find that: (1) the yields of the intermediate mass elements (i.e., O to P) show a steep decrease as the initial mass decreases; (2) the yields of s -weak components, i.e., those produced by the slow neutron captures from Ga to to the first neutron closure shell, decrease almost linearly as a function of the initial mass with respect to the ones produced by the more massive stars; and (3) the global contribution of the stars in the mass range 9.22−13 M ⊙ to the yields of a generation of massive stars averaged over a standard initial mass function is negligible for essentially all the isotopes. In spite of this, however, the models of stars in this mass range can be fundamental to interpreting the observations of specific supernovae.