The physics of proto-neutron star winds: Implications for r-process nucleosynthesis

Todd A. Thompson, Adam Burrows, Bradley S. Meyer

Research output: Contribution to journalArticle

225 Scopus citations

Abstract

We solve the general-relativistic steady-state eigenvalue problem of neutrino-driven proto-neutron star winds, which immediately follow core-collapse supernova explosions. We provide velocity, density, temperature, and composition profiles and explore the systematics and structures generic to such a wind for a variety of proto-neutron star characteristics. Furthermore, we derive the entropy, dynamical timescale, and neutron-to-seed ratio in the general relativistic framework essential in assessing this site as a candidate for r-process nucleosynthesis. Generally, we find that for a given mass outflow rate (Ṁ), the dynamical timescale of the wind is significantly shorter than previously thought. We argue against the existence or viability of a high entropy (≳300 per kB per baryon), long dynamical timescale r-process epoch. In support of this conclusion, we model the proto-neutron star cooling phase, calculate nucleosynthetic yields in our steady-state profiles, and estimate the integrated mass loss. We find that transonic winds enter a high-entropy phase only with very low Ṁ (≲1 × 10-9 M s-1) and extremely long dynamical timescale (τρ ≳ 0.5 s). Our results support the possible existence of an early r-process epoch at modest entropy (∼150) and very short dynamical timescale, consistent in our calculations with a very massive or very compact proto-neutron star that contracts rapidly after the preceding supernova. We explore possible modifications to our models, which might yield significant r-process nucleosynthesis generically. Finally, we speculate on the effect of fallback and shocks on both the wind physics and nucleosynthesis. We find that a termination or reverse shock in the wind, but exterior to the wind sonic point, may have important nucleosynthetic consequences. The potential for the r-process in proto-neutron star winds remains an open question.

Original languageEnglish (US)
Pages (from-to)887-908
Number of pages22
JournalAstrophysical Journal
Volume562
Issue number2 PART II
DOIs
StatePublished - Jan 1 2001
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Keywords

  • Nuclear reactions, nucleosynthesis, abundances
  • Stars: mass loss stars: neutron
  • Supernovae: general

Fingerprint Dive into the research topics of 'The physics of proto-neutron star winds: Implications for r-process nucleosynthesis'. Together they form a unique fingerprint.

  • Cite this