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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

We apply Markov Chain Monte Carlo to predict the masses required to form the observed solar $r$-process rare-earth abundance peak. Given highly distinct astrophysical outflows and nuclear inputs, we find that results are most sensitive to…

Nuclear Theory · Physics 2022-02-22 Nicole Vassh , Gail C. McLaughlin , Matthew R. Mumpower , Rebecca Surman

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

The surface chemical compositions of a large fraction of Carbon-Enhanced Metal-Poor (CEMP) stars, the so-called CEMP-r/s stars, are known to exhibit enhancement of both s- and r-process elements. For these stars, the heavy element…

Solar and Stellar Astrophysics · Physics 2021-01-06 Partha Pratim Goswami , Aruna Goswami

The considerable scatter of the s- and r-process elements observed in low-metallicity stars, compared to the small star to star scatter observed for the alpha elements, is an open question for the chemical evolution studies. We have…

Astrophysics · Physics 2007-05-23 G. Cescutti

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

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

This work describes a study of elemental abundances for 30 metal-poor stars whose chemical abundances provide excellent information for setting constraints on models of neutron-capture processes. Based on the abundances of main r- and weak…

Solar and Stellar Astrophysics · Physics 2015-06-12 Hongjie Li , Xiaojing Shen , Shuai Liang , Wenyuan Cui , Bo Zhang

The dispersion and mean trends of r-process abundances in metal-poor stars are discussed based on a model of diverse supernova sources for the r-process. This model is unique in that its key parameters are inferred from solar system data…

Astrophysics · Physics 2009-11-06 Y. -Z. Qian

We determined the \fodd\ values, $0.46\pm0.08$, $0.51\pm0.09$, $0.50\pm0.13$, $0.48\pm0.12$, which correspond to the r-contribution 100\% for four r-II stars, \cs, \hen, \hes\, and \het, respectively. Our results suggest that almost all of…

Solar and Stellar Astrophysics · Physics 2018-01-25 Wenyuan Cui , Xiaohua Jiang , Jianrong Shi , Gang Zhao , Bo Zhang

The rapid neutron capture process (r-process) is thought to be responsible for the creation of more than half of all elements beyond iron. The scientific challenges to understanding the origin of the heavy elements beyond iron lie in both…

Nuclear Theory · Physics 2015-06-12 S. Brett , I. Bentley , N. Paul , R. Surman , A. Aprahamian

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

Many works have attempted to investigate the astrophysical origin of the neutron-capture elements in the metalpoor star HD 140283. However, no definite conclusions have been drawn. In this work, using the abundancedecomposed approach, we…

Solar and Stellar Astrophysics · Physics 2015-11-17 Ping Niu , Wenyuan Cui , Bo Zhang

The heavy elements formed by neutron capture processes have an interesting history from which we can extract useful clues to and constraints upon both the characteristics of the processes themselves and the star formation and…

Astrophysics · Physics 2009-11-07 J. W. Truran , J. J. Cowan , C. A. Pilachowski , C. Sneden

The type II supernova is considered as a candidate site for the production of heavy elements. Since the supernova produces an intense neutrino flux, neutrino scattering processes will impact element formation. We examine active-sterile…

High Energy Physics - Phenomenology · Physics 2009-10-31 G. C. McLaughlin

Recent calculations place questions on the ability of supernovae to produce r-process nuclei in the correct amounts. We present results from 3D Newtonian SPH calculations of mergers of equal mass neutron star binaries. We find the amounts…

Astrophysics · Physics 2016-08-30 S. Rosswog , F. -K. Thielemann , M. B. Davies , W. Benz , T. Piran

The merger of two neutron stars or of a neutron star and a black hole often result in the ejection of a few percents of a solar mass of matter expanding at high speed in space. Being matter coming from the violent disruption of a neutron…

High Energy Astrophysical Phenomena · Physics 2021-12-21 Albino Perego , Friedrich-Karl Thielemann , Gabriele Cescutti

We study turbulent gas diffusion affects on $r$-process abundances in Milky Way stars, by a combination of an analytical approach and a Monte Carlo simulation. Higher $r$-process event rates and faster diffusion, lead to more efficient…

High Energy Astrophysical Phenomena · Physics 2020-06-24 Paz Beniamini , Kenta Hotokezaka

The focus of the present review is the production of the heaviest elements in nature via the r-process. A correct understanding and modeling requires the knowledge of nuclear properties far from stability and a detailed prescription of the…

Astrophysics · Physics 2009-10-31 K. -L. Kratz , B. Pfeiffer , F. -K. Thielemann , W. B. Walters

A variety of physical processes leading to different types of pulsations and chemical compositions is observed among A- and F-type stars. To investigate the underlying mechanisms responsible for these processes in stars with similar…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. Hekker , Y. Fremat , P. Lampens , P. De Cat , E. Niemczura , O. L. Creevey , J. Zorec
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