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Related papers: Recent Progress in the Understanding of the r-Proc…

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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

Some nuclear and astrophysical aspects of the r-process are discussed. Particular attention is paid to observations of abundances in metal-poor stars and their implications for the astrophysical site and yield patterns of the r-process. The…

Astrophysics · Physics 2009-11-10 Y. -Z. Qian

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…

Extensive progress has been recently made into our understanding of heavy element production via the $r$-process in the Universe, specifically with the first observed neutron star binary merger (NSBM) event associated with the gravitational…

We investigate nuclear reactions and feedback in hyperaccreting neutron star environments, considering accretion rates in the range 0.3 - $3\times10^4$ $M_\odot$ yr$^{-1}$, typical of short-period compact object binaries in common…

High Energy Astrophysical Phenomena · Physics 2025-11-25 Peter Anninos , Matthew Portman , Scott Carmichael , Robert Hoffman , Andre Sieverding

We examine the Pb and Th abundances in 27 metal-poor stars (-3.1 < [Fe/H] < -1.4) whose very heavy metal (Z > 56) enrichment was produced only by the rapid (r-) nucleosynthesis process. New abundances are derived from HST/STIS, Keck/HIRES,…

Solar and Stellar Astrophysics · Physics 2011-02-11 Ian U. Roederer , Karl-Ludwig Kratz , Anna Frebel , Norbert Christlieb , Bernd Pfeiffer , John J. Cowan , Christopher Sneden

The discovery of the second highly $r$-process-enhanced, extremely metal-poor star, CS 31082-001 ([Fe/H] $= -2.9$) has provided a powerful new tool for age determination, by virtue of the detection and measurement of the radioactive species…

Astrophysics · Physics 2009-11-07 Shinya Wanajo , Naoki Itoh , Yuhri Ishimaru , Satoshi Nozawa , Timothy C. Beers

Abundances of low-metallicity stars offer a unique opportunity to understand the contribution and conditions of the different processes that synthesize heavy elements. Many old, metal-poor stars show a robust abundance pattern for elements…

Solar and Stellar Astrophysics · Physics 2015-01-12 C. J. Hansen , F. Montes , A. Arcones

A small number of naturally occurring, proton-rich nuclides (the p-nuclei) cannot be made in the s- and r-process. Their origin is not well understood. Massive stars can produce p-nuclei through photodisintegration of pre-existing…

Solar and Stellar Astrophysics · Physics 2013-05-14 T. Rauscher , N. Dauphas , I. Dillmann , C. Fröhlich , Zs. Fülöp , Gy. Gyürky

Neutrino-driven winds are thought to accompany the Kelvin-Helmholtz cooling phase of nascent protoneutron stars in the first seconds after a core-collapse supernova. These outflows are a likely candidate as the astrophysical site for rapid…

Astrophysics · Physics 2015-12-02 Todd A. Thompson

Abundance observations indicate the presence of rapid-neutron capture (i.e., r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the…

Astrophysics · Physics 2009-09-29 J. J. Cowan , C. Sneden , J. E. Lawler , E. A. Den Hartog

I show that recent observations of r-process abundances in metal-poor stars are difficult to explain if neutron star mergers (NSMs) are the major r-process sources. In contrast, such observations and meteoritic data on Hf182 and I129 in the…

Astrophysics · Physics 2009-10-31 Y. -Z. Qian

The production of elements by rapid neutron capture (r-process) in neutron-star mergers is expected theoretically and is supported by multimessenger observations of gravitational-wave event GW170817: this production route is in principle…

High Energy Astrophysical Phenomena · Physics 2020-08-17 Daniel M. Siegel , Jennifer Barnes , Brian D. Metzger

We investigated r-process nucleosynthesis in magneto-rotational supernovae, based on a new explosion mechanism induced by the magneto-rotational instability. A series of axisymmetric magneto-hydrodynamical simulations with detailed…

High Energy Astrophysical Phenomena · Physics 2017-02-16 Nobuya Nishimura , Hidetomo Sawai , Tomoya Takiwaki , Shoichi Yamada , Friedrich-Karl Thielemann

To better characterize the abundance patterns produced by the r-process, we have derived new abundances or upper limits for the heavy elements zinc (Zn), yttrium (Y), lanthanum (La), europium (Eu), and lead (Pb). Our sample of 161…

Solar and Stellar Astrophysics · Physics 2015-05-20 I. U. Roederer , J. J. Cowan , A. I. Karakas , K. -L. Kratz , M. Lugaro , J. Simmerer , K. Farouqi , C. Sneden

We explore heavy-element nucleosynthesis by rapid neutron capture (r-process) in the decompressing ejecta from the surface of a neutron star. The decompression is triggered by a violent phase transition to strange quark matter (quark-nova…

Nuclear Theory · Physics 2009-03-19 Prashanth Jaikumar , Bradley S. Meyer , Kaori Otsuki , Rachid Ouyed

Nuclear masses play a fundamental role in understanding how the heaviest elements in the Universe are created in the $r$-process. We predict $r$-process nucleosynthesis yields using neutron capture and photodissociation rates that are based…

Nuclear Theory · Physics 2016-03-30 Dirk Martin , Almudena Arcones , Witold Nazarewicz , Erik Olsen

Theoretical studies of the nucleosynthesis origin of the heavy elements in our Solar System (S.S.) by the rapid neutron-capture process (r-process) still face the entwined uncertainties in the possible astrophysical scenarios and the…

Solar and Stellar Astrophysics · Physics 2015-06-19 Karl-Ludwig Kratz , Khalil Farouqi , Peter Möller

The supernova yields of r-process elements are obtained as a function of the mass of their progenitor stars from the abundance patterns of extremely metal-poor stars on the left-side [Ba/Mg]-[Mg/H] boundary with a procedure proposed by…

Astrophysics · Physics 2008-11-26 Zhe Chen , Jiang Zhang , YanPing Chen , WenYuan Cui , Bo Zhang

The chemical abundances of metal-poor stars are an excellent test bed by which to set new constraints on models of neutron-capture processes at low metallicity. Some r-process-rich (hereafter r-rich) metal-poor stars, such as HD221170, show…

Solar and Stellar Astrophysics · Physics 2010-10-25 Jiang Zhang , Wenyuan Cui , Bo Zhang
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