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The synthesis of hyper-heavy elements is investigated under conditions simulating neutron star environment. The Constrained Molecular Dynamics (CoMD) approach is used to simulate low energy collisions of extremely n-rich nuclei. A new type…

Nuclear Theory · Physics 2022-07-27 M. Veselsky , V. Petousis , Ch. C. Moustakidis , G. A. Souliotis , A. Bonasera

It has been recently proposed that the shocked surface layers of exploding O-Ne-Mg cores provide the conditions for r-process nucleosynthesis, because their rapid expansion and high entropies enable heavy r-process isotopes to form even in…

Astrophysics · Physics 2009-11-13 H. -Th. Janka , B. Mueller , F. S. Kitaura , R. Buras

We propose a $(p,xn)$ mechanism with dynamic production as a new set of nuclear reactions that could produce high density neutrons and explain the r- and rp-elements. We calculate the rate of thorium and uranium produced by our proposed…

Nuclear Theory · Physics 2020-09-04 Pedro V. Guillaumon , Iuda D. Goldman

We study the role of light neutron-rich nuclei during r-process nucleosynthesis in supernovae. Most previous studies of the r-process have concentrated on the reaction flow of heavy unstable nuclei. Although the nuclear reaction network…

Astrophysics · Physics 2009-11-06 M. Terasawa , K. Sumiyoshi , T. Kajino , G. J. Mathews , I. Tanihata

Long-term ideal and resistive magnetohydrodynamics (MHD) simulations in full general relativity are performed for a massive neutron star formed as a remnant of binary neutron star mergers. Neutrino radiation transport effects are taken into…

High Energy Astrophysical Phenomena · Physics 2021-03-17 Masaru Shibata , Sho Fujibayashi , Yuichiro Sekiguchi

Although the rapid neutron-capture process, or r-process, is fundamentally important for explaining the origin of approximately half of the stable nuclei with A > 60, the astrophysical site of this process has not been identified yet. Here…

Solar and Stellar Astrophysics · Physics 2015-05-28 Stephane Goriely , Andreas Bauswein , H. -Thomas Janka

The neutrino driven wind during a core collapse supernova is an attractive site for r-process nucleosynthesis. The electron fraction $Y_e$ in the wind depends on observable neutrino energies and luminosities. The mean antineutrino energy is…

Astrophysics · Physics 2009-11-07 C. J. Horowitz

A long-standing scientific puzzle has been to explain the origin of the heaviest elements in the Universe and, more particularly, the production of the elements heavier than iron up to uranium. The rapid neutron capture process (or…

High Energy Astrophysical Phenomena · Physics 2023-03-14 Ina K. B. Kullmann

We perform hydrodynamic supernova simulations in spherical symmetry for over 100 single stars of solar metallicity to explore the progenitor-explosion and progenitor-remnant connections established by the neutrino-driven mechanism. We use…

Solar and Stellar Astrophysics · Physics 2015-06-05 Marcella Ugliano , H. -Thomas Janka , Andreas Marek , Almudena Arcones

This manuscript reviews recent progress in our understanding of the nucleosynthesis of medium and heavy elements in supernovae. Recent hydrodynamical models of core-collapse supernovae show that a large amount of proton rich matter is…

The r-process in a low temperature environment is explored, in which the neutron emission by photodisintegration does not play a role (cold r-process). A semi-analytic neutrino-driven wind model is utilized for this purpose. The temperature…

Astrophysics · Physics 2009-11-13 Shinya Wanajo

To study properties of magneto-hydrodynamic (MHD) convection and resultant dynamo activities in proto-neutron stars (PNSs), we construct a "PNS in a box" simulation model with solving compressible MHD equation coupled with a nuclear…

High Energy Astrophysical Phenomena · Physics 2022-02-21 Youhei Masada , Tomoya Takiwaki , Kei Kotake

Several gamma ray bursts have recently been associated with a kilonova emission. We study the mechanisms which could account for this effect, by means of radioactive decay of elements synthesized in accretion disk wind. We model the…

High Energy Astrophysical Phenomena · Physics 2026-03-18 Agnieszka Janiuk , Joseph Saji , Gerardo Urrutia

The rapid-neutron-capture ("r") process is responsible for synthesizing many of the heavy elements observed in both the solar system and Galactic metal-poor halo stars. Simulations of r-process nucleosynthesis can reproduce abundances…

During the merger of a black hole and a neutron star, baryonic mass can become unbound from the system. Because the ejected material is extremely neutron-rich, the r-process rapidly synthesizes heavy nuclides as the material expands and…

We present a coherent study of the impact of neutrino interactions on the r-process element nucleosynthesis and the heating rate produced by the radioactive elements synthesised in the dynamical ejecta of neutron star-neutron star (NS-NS)…

High Energy Astrophysical Phenomena · Physics 2021-11-23 I. Kullmann , S. Goriely , O. Just , R. Ardevol-Pulpillo , A. Bauswein , H. -T. Janka

All the current r-process scenarios relevant to core-collapse supernovae are facing severe difficulties. In particular, recent core-collapse simulations with neutrino transport show no sign of a neutron-rich wind from the proto-neutron…

Solar and Stellar Astrophysics · Physics 2015-05-19 Shinya Wanajo , Hans-Thomas Janka

LS 5039 hosts a high-mass star, and a compact object that might be a strongly magnetized neutron star (NS). This scenario requires a mechanism to power its persistent and strong nonthermal emission. We investigate a mechanism in which the…

High Energy Astrophysical Phenomena · Physics 2025-11-26 V. Bosch-Ramon , M. V. Barkov

About half of the heavy elements in the Solar System were created by rapid neutron capture, or r-process, nucleosynthesis. In the r-process, heavy elements are built up via a sequence of neutron captures and beta decays in which an intense…

Nuclear Theory · Physics 2017-08-23 R. Surman , M. Mumpower , J. Cass , A. Aprahamian

We revisit a neutrino-driven r-process mechanism in the He shell of a core-collapse supernova, finding that it could succeed in early stars of metallicity < solar/1000, at relatively low temperatures and neutron densities, producing A ~ 130…

Solar and Stellar Astrophysics · Physics 2011-07-11 P. Banerjee , W. C. Haxton , Y. -Z. Qian