NUCLEOSYNTHESIS in NEUTRINO-DRIVEN WINDS in HYPERNOVAE

Abstract

We investigate the nucleosynthesis in the neutrino-driven winds blown off from a 3 M⊙ massive proto-neutron star (mPNS) temporarily formed during the collapse of a 100 M⊙ star. Such mPNSs would be formed in hypernovae. We construct steady and spherically symmetric wind solutions. We set large neutrino luminosities of∼1053 erg s-1 and average energies of electron neutrinos and antineutrinos in the ranges of εve = 9-16 MeV and εv¯e = 11-18 MeV based on a recent numerical relativity simulation. The wind solutions indicate a temperaturedecrease timescale much shorter than that of the winds from ordinary PNSs, and, depending on εv , the winds can be both neutron-rich and proton-rich. In the neutron-rich wind, the r-process occurs and the abundance distribution of a fiducial wind model of the mPNS gives an approximate agreement with the abundance pattern of metal-poor weak r star HD 122563, although the third-peak elements are produced only when the v¯e energy is much larger than the ve energy. In the proton-rich wind, the strong vp-process occurs and A > 100 nuclides are synthesized. The synthesized nuclei can be neutron-rich in some cases because the large neutrino luminosity of the mPNS supplies a sufficient amount of neutrons.