中文
相关论文

相关论文: What we do and do not know about the s-process

200 篇论文

High dispersion near-infrared spectra have been taken of seven highly-evolved, variable, intermediate-mass (4-6 Msun) AGB stars in the LMC and SMC in order to look for C, N and O variations that are expected to arise from third dredge-up…

天体物理学 · 物理学 2009-11-13 J. A. McSaveney , P. R. Wood , M. Scholz , J. C. Lattanzio , K. H. Hinkle

Light and intermediate nuclei as well as s-process elements have been detected in presolar grains and in evolved red giants. The abundances of some of these nuclei cannot be accounted for by canonical stellar models and require…

星系天体物理 · 物理学 2010-12-14 M. Busso , E. Maiorca , L. Magrini , S. Randich , S. Palmerini , S. Cristallo

The abundances of the slow neutron-capture (s-) process elements observed in barium stars can be explained by considering mass transfer in a binary system from an asymptotic giant branch (AGB) star onto a smaller mass and less evolved…

太阳与恒星天体物理 · 物理学 2023-11-17 Partha Pratim Goswami , Aruna Goswami

The Carbon-Nitrogen-Oxygen (CNO) cycle is fundamental to the process of hydrogen burning in stars, serving as a pivotal mechanism. At its core, the primary reaction involves the radiative capture of a proton by $^{12}$C, crucially…

核理论 · 物理学 2024-05-31 Soumya Saha

The discovery of a historical bug in the s-post-process AGB code obtained so far by the Torino group forced us to reconsider the role of primary 16O in the 13C-pocket, produced by the 13C(a, n)16O reaction, as important neutron poison for…

太阳与恒星天体物理 · 物理学 2015-03-17 R. Gallino , S. Bisterzo , S. Cristallo , O. Straniero

The ejecta of the first probably very massive stars polluted the Big Bang primordial element mix with the first heavier elements. The resulting ultra metal-poor abundance distribution provided the initial conditions for the second stars of…

天体物理学 · 物理学 2007-08-30 Falk Herwig

Uncertainties in nucleosynthesis models originating from uncertainties in astrophysical reaction rates were estimated in a Monte Carlo variation procedure. Thousands of rates were simultaneously varied within individual,…

太阳与恒星天体物理 · 物理学 2018-06-05 T. Rauscher , N. Nishimura , G. Cescutti , R. Hirschi , A. St. J. Murphy

We report a new mechanism for the \textsl{s} in rotating massive metal-poor stars. Our models show that above a critical rotation speed, such stars evolve in a quasi-chemically-homogeneous fashion, which gives rise to a prolific…

太阳与恒星天体物理 · 物理学 2021-10-28 Projjwal Banerjee , Alexander Heger , Yong-Zhong Qian

Context: It is well known that the so-called s-process is responsible for the production of neutron-rich trans-iron elements, that form the bulk of the "heavy nuclides" (i.e. nuclides more massive than the iron-group nuclei) in the…

太阳与恒星天体物理 · 物理学 2012-03-21 M. L. Pumo

The main s-process taking place in low mass stars produces about half of the elements heavier than iron. It is therefore very important to determine the importance and impact of nuclear physics uncertainties on this process. We have…

太阳与恒星天体物理 · 物理学 2018-06-28 G. Cescutti , R. Hirschi , N. Nishimura , J. W. den Hartogh , T. Rauscher , A. St. J. Murphy , S. Cristallo

In this review, we emphasize the interplay between astrophysical observations, modeling, and nuclear physics laboratory experiments. Several important nuclear cross sections for astrophysics have long been identified e.g.…

核实验 · 物理学 2016-05-26 Alain Coc , Fairouz Hammache , Juergen Kiener

The astrophysical origin of the rapid neutron-capture process (r-process), which produces about half of the elements heavier than iron, remains uncertain. The oldest, most metal-poor stars preserve the chemical signatures of early…

We report Mo isotopic data of 27 new presolar SiC grains, including 12 14N-rich AB (14N/15N>440, AB2) and 15 mainstream (MS) grains, and their correlated Sr and Ba isotope ratios when available. Direct comparison of the data for the MS…

Carbon-enhanced metal-poor (CEMP) r/s-stars show surface-abundance distributions characteristic of the so-called intermediate neutron capture process (i-process) of nucleosynthesis. We previously showed that the ingestion of protons in the…

太阳与恒星天体物理 · 物理学 2021-10-27 S. Goriely , L. Siess , A. Choplin

Alongside the slow (s) and rapid (r) neutron capture processes, an intermediate neutron capture process (i-process) is thought to exist. It happens when protons are mixed in a convective helium-burning zone, and is referred to as proton…

太阳与恒星天体物理 · 物理学 2022-11-23 A. Choplin , L. Siess , S. Goriely

The production of the neutron-capture isotopes beyond iron that we observe today in the solar system is the result of the combined contribution of the r-process, the s- process and possibly the i-process. Low-mass AGB (2 < M/Msun < 3) and…

We demonstrate that a massive asymptotic giant branch (AGB) star is a good candidate as the main source of short-lived radionuclides in the early solar system. Recent identification of massive (4-8 solar masses) AGB stars in the Galaxy,…

Precise mechanisms by which Active Galactic Nuclei (AGN) receive their gaseous fuel is still a mystery. Here I draw attention to the extra ordinary star formation event that took place in the central ~ 0.5 parsec of our Galaxy. The most…

天体物理学 · 物理学 2007-05-23 Sergei Nayakshin

The recent parameterisation by the GSP-spec module of Gaia/RVS spectra has produced an homogeneous catalogue of about 174,000 AGB stars. Among the 13 chemical elements presented in this catalogue, the abundance of 2 of them (Ce and Nd) have…

太阳与恒星天体物理 · 物理学 2024-01-02 G. Contursi , P. de Laverny , A. Recio-Blanco , P. A. Palicio , C. Abia

We study the impact of nuclear input related to weak-decay rates and neutron-capture reactions on predictions for the $s$ process in AGB stars. We provide the first database of surface abundances and stellar yields of the isotopes heavier…

太阳与恒星天体物理 · 物理学 2025-05-07 B. Szányi , A. Yagüe López , A. I. Karakas , M. Lugaro