arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1901.01410astro-ph.HEnucl-exnucl-th
收藏

最重元素的起源:快速中子俘获过程

Origin of the Heaviest Elements: the Rapid Neutron-Capture Process

John J. Cowan, Christopher Sneden, James E. Lawler, Ani Aprahamian, Michael Wiescher, Karlheinz Langanke, Gabriel Martínez-Pinedo, Friedrich-Karl Thielemann

摘要:

在自然界中发现的重元素中,约有一半是由一个特殊的天体物理核合成过程产生的:快速中子俘获过程(r-过程)。虽然这一想法在60多年前就已经提出,但全面理解面临着两种类型的不确定性/未决问题:(a)核图表中的核合成路径靠近中子滴线,目前只有有限的实验信息可用,并且必须强烈依赖于对核性质的理论预测。(b)虽然多年来r-过程的发生一直与超新星有关,但最近的研究对这种环境提出了实质性的质疑。替代方案包括中子星合并,中子星黑洞合并,但也可能是罕见的超新星,以及极喷流喷出物和吸积盘流出与快速旋转的大质量恒星的崩溃与高磁场的超新星/超新星。恒星r-过程丰度观测,提供了洞察力,并限制在负责任的恒星生产网站的频率和条件。其中之一,中子星合并,刚刚确定和有关的引力波事件GW 170817。高分辨率的观测,由于实验原子数据的改进而越来越精确,在确定旧晕星的重元素丰度模式方面特别重要,从而确定我们银河系最早的核合成的程度和性质。本文结合核、原子和天文科学领域的新成果和重大突破,试图回答“从铁到铀的元素是如何形成的?”这一问题。“(节略)

英文摘要:

The production of about half of the heavy elements found in nature is assigned to a specific astrophysical nucleosynthesis process: the rapid neutron capture process (r-process). Although this idea has been postulated more than six decades ago, the full understanding faces two types of uncertainties/open questions: (a) The nucleosynthesis path in the nuclear chart runs close to the neutron-drip line, where presently only limited experimental information is available, and one has to rely strongly on theoretical predictions for nuclear properties. (b) While for many years the occurrence of the r-process has been associated with supernovae, more recent studies have cast substantial doubts on this environment. Alternative scenarios include the mergers of neutron stars, neutron-star black hole mergers, but possibly also rare classes of supernovae as well as hypernovae/collapsars with polar jet ejecta and also accretion disk outflows related to the collapse of fast rotating massive stars with high magnetic fields. Stellar r-process abundance observations, have provided insights into, and constraints on the frequency of and conditions in the responsible stellar production sites. One of them, neutron star mergers, was just identified and related to the Gravitational Wave event GW170817. High resolution observations, increasingly more precise due to improved experimental atomic data, have been particularly important in defining the heavy element abundance patterns of the old halo stars, and thus determining the extent, and nature, of the earliest nucleosynthesis in our Galaxy. Combining new results and important breakthroughs in the related nuclear, atomic and astronomical fields of science, this review attempts to provide an answer to the question "How Were the Elements from Iron to Uranium Made?" (Abridged)

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑