Neutrino-driven wind simulations and nucleosynthesis of heavy elements

Abstract

Abstract. Neutrino-driven winds, which follow core-collapse supernova explosions, present a fascinating nuclear astrophysics problem that requires understanding advanced astrophysics simulations, the properties of matter and neutrino interactions under extreme conditions, the structure and reactions of exotic nuclei, and comparisons against forefront astronomical observations. The neutrino-driven wind has attracted vast attention over the last 20 years as it was suggested to be a candidate for the astrophysics site where half of the heavy elements are produced via the r-process. In this review, we summarize our present understanding of neutrino-driven winds from the dynamical and nucleosynthesis perspectives. Rapid progress has been made during recent years in understanding the wind with improved simulations and better micro physics. The current status of the fields is that hydrodynamical simulations do not reach the extreme conditions necessary for the r-process and the proton or neutron richness of the wind remains to be investigated in more detail. However, nucleosynthesis studies and observations point already to neutrino-driven winds to explain the origin of lighter heavy elements, such as Sr, Y, Zr.

The Intermediate r-process in Core-collapse Supernovae Driven by the Magneto-rotational Instability

“…The h-model(+) shows slightly less A 130 peak production, suppressed by stronger neutrino absorption. Nevertheless, a significant amount of lighter r-process nuclei is ejected in the h-model, which is difficult in the proto-NS winds of CC-SNe (Arcones & Thielemann 2013). The i-model exhibits different nucleosynthesis features, which the abundances of heavy nuclei are between the mand h-models, as expected by the Y e -S distribution.…”

“…The existence of fast rotating massive stars at early galaxies is also supported by detection of Ba and La in metal-poor stars (Chiappini et al 2011), which is explained by the enhanced s-process via strong rotational-induced mixing (Frischknecht et al 2012;Nishimura et al 2017). Even if MRSNe are only active in early galaxies, they can be responsible for the production of r-process elements by the entire CC-SNe in Galactic chemical evolution (GCE) because canonical CC-SNe produce only the lighter end of heavy nuclei in their proto-neutron star (proto-NS) winds (e.g., Arcones & Thielemann 2013).…”

Galactic evolution of rapid neutron capture process abundances: the inhomogeneous approach

“…They provide an important contribution to other α-elements (S, Ca, Ti), to all intermediate-mass elements, the iron-group elements and to the s-process species up to the Sr neutron-magic peak (e.g., Rauscher et al 2002). Associated to CCSNe, different neutrino-driven nucleosynthesis components might be ejected and contribute to the GCE (e.g., Arcones & Thielemann 2013, and references therein), possibly including the r-process. We did not include regular CCSNe as a major source of heavy r-process elements, as recent investigations indicate strongly that the early hopes for a high entropy neutrino wind with the right properties (Woosley et al 1994, Takahashi et al 1994 did not survive advanced core collapse simulations (e.g., Liebendörfer et al 2003) which led to proton-rich environments in the innermost ejecta (see also Fischer et al 2010, Hüdepohl et al 2010), causing rather a so-called νp-process (Fröhlich et al 2006a, Fröhlich et al 2006b, Pruet et al 2005, Pruet et al 2006, Wanajo 2006.…”

An r-process Enhanced Star in the Dwarf Galaxy Tucana III*

“…Since many stars with r-process enhancements are therefore not in binaries, the unusual abundance patterns of the r-I and r-II stars must be the result of nucleosynthesis events in the early universe. The suggested astrophysical sites for production of r-process elements include neutron star mergers (NSMs; e.g., Lattimer & Schramm 1974;Meyer 1989;Freiburghaus et al 1999;Metzger et al 2010;Goriely et al 2011;Korobkin et al 2012;Bauswein et al 2013;Rosswog et al 2014) and various types of supernovae (SNe), including magnetorotationally driven SNe (also known as jet SNe; Cameron 2003;Fujimoto et al 2008;Winteler et al 2012) and neutrino-driven winds in core-collapse SNe (Arcones & Thielemann 2013 and references therein). The NSMs and jet SNe are referred to as main r-process sites and can produce the heavy r-process elements.…”