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A brief overview of the r-process is given with an emphasis on the observational implications for this process. The conditions required for the major production of the heavy r-process elements (r-elements) with mass numbers A >130 are…

Astrophysics · Physics 2008-09-18 Yong-Zhong Qian

We examine r-process nucleosynthesis in a "prompt supernova explosion" from an 8-10 Msun progenitor star, as an alternative scenario to the "neutrino wind" mechanism. In the present model, the progenitor star has formed an…

Astrophysics · Physics 2011-07-19 S. Wanajo , M. Tamamura , N. Itoh , K. Nomoto , Y. Ishimaru , T. C. Beers , S. Nozawa

We present a review of the possible sources for r-process nuclei. It is known that there is as yet no self-consistent mechanism to provide abundant neutrons for a robust r-process in the neutrino-driven winds from nascent neutron stars. We…

Astrophysics · Physics 2010-11-11 Y. -Z. Qian , G. J. Wasserburg

We present calculations of r-process nucleosynthesis in neutrino-driven winds from the nascent neutron stars of core-collapse supernovae. A full dynamical reaction network for both the alpha-rich freezeout and the subsequent r-process is…

Astrophysics · Physics 2009-11-06 Shinya Wanajo , Toshitaka Kajino , Grant J. Mathews , Kaori Otsuki

I compare seven actively studied r-process nucleosynthesis scenarios against observed properties of r-process elements in the early Universe, and conclude that the most likely scenario to contribute to the site of elements below the third…

High Energy Astrophysical Phenomena · Physics 2026-05-12 Noam Soker

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

We use observations of heavy elements in very metal-poor stars ([Fe/H] < -2.5) in order to place constraints on the viability of collapsar models as a significant source of the r-process. We combine bipolar explosion nucleosynthesis…

High Energy Astrophysical Phenomena · Physics 2019-06-05 Phillip Macias , Enrico Ramirez-Ruiz

We analyze data from several studies of metal-poor stars in the Milky Way, focusing on both strong (Eu) and weak (Sr) $r$-process elements. Because these elements were injected in an explosion, we calculate the mass swept up when the blast…

High Energy Astrophysical Phenomena · Physics 2018-09-12 Phillip Macias , Enrico Ramirez-Ruiz

There has been a persistent conundrum in attempts to model the nucleosynthesis of heavy elements by rapid neutron capture (the $r$-process). Although the location of the abundance peaks near nuclear mass numbers 130 and 195 identify an…

Solar and Stellar Astrophysics · Physics 2016-01-27 S. Shibagaki , T. Kajino , G. J. Mathews , S. Chiba , S. Nishimura , G. Lorusso

The chemical abundances of metal-poor stars provide important clues to explore stellar formation history and set significant constraints on models of the r-process. In this work, we find that the abundance patterns of the light and iron…

Solar and Stellar Astrophysics · Physics 2014-07-21 Hongjie Li , Wenjuan Ma , Wenyuan Cui , Bo Zhang

Nucleosynthesis of heavy nuclei in metal-poor stars is generally thought to occur via the r-process because the r-process is a primary process that would have operated early in the Galaxy's history. This idea is strongly supported by the…

Solar and Stellar Astrophysics · Physics 2015-06-03 Richard Boyd , Michael Famiano , Bradley Meyer , Yuko Motizuki , Toshitaka Kajino , Ian Roederer

Various nucleosynthesis studies have pointed out that the r-process elements in very metal-poor (VMP) halo stars might have different origins. By means of familiar concepts from statistics (correlations, cluster analysis, rank tests of…

Solar and Stellar Astrophysics · Physics 2022-07-20 Khalil Farouqi , Friedrich-Karl Thielemann , Stephan Rosswog , Karl-Ludwig Kratz

(Abridged) The stellar sites and the complete mechanism of r-process nucleosynthesis are still unresolved issues. From consideration of the observed abundances in metal-poor stars, it is proposed that the production of the heavy r-process…

Astrophysics · Physics 2009-11-07 Y. -Z. Qian , G. J. Wasserburg

We examine the r-process in the neutrino-driven proto-neutron-star (PNS) wind of core-collapse supernovae in light of the recent findings of massive neutron stars in binaries as well as of an indication of neutron-richness in the PNS ejecta…

Solar and Stellar Astrophysics · Physics 2015-06-15 Shinya Wanajo

We study the r-process nucleosynthesis in neutrino-driven winds of gravitational core collapse SNeII. Appropriate physical conditions are found for successful r-process nucleosynthesis, which meet with several features of heavy elements…

Astrophysics · Physics 2015-06-24 T. Kajino , S. Wanajo , G. J. Mathews

Abundances of heavier elements (barium and beyond) in many neutron-capture-element-rich halo stars accurately replicate the solar system r-process pattern. However, abundances of lighter neutron-capture elements in these stars are not…

The abundances of r-process elements of very metal-poor stars capture the history of the r-process enrichment in the early stage of star formation in a galaxy. Currently, various types of astrophysical sites including neutron star mergers,…

Astrophysics of Galaxies · Physics 2021-06-09 Yuta Tarumi , Kenta Hotokezaka , Paz Beniamini

The astrophysical nature of r-process sites is a long standing mystery and many probable sources have been suggested in the past, among them lower-mass core-collapse supernovae (in the range 8 - 10 Msol), higher-mass core-collapse…

Astrophysics · Physics 2009-11-10 D. Argast , M. Samland , F. -K. Thielemann , Y. -Z. Qian

The r-process, or the rapid neutron-capture process, of stellar nucleosynthesis is called for to explain the production of the stable (and some long-lived radioactive) neutron-rich nuclides heavier than iron that are observed in stars of…

Astrophysics · Physics 2008-11-26 M. Arnould , S. Goriely , K. Takahashi

We use network calculations of r-process nucleosynthesis to explore the origin of the peak in the solar r-process abundance distribution near nuclear mass number A = 160. The peak is due to a subtle interplay of nuclear deformation and beta…

Astrophysics · Physics 2016-08-30 R. Surman , J. Engel , J. R. Bennett , B. S. Meyer
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