The discovery of gravitational waves has confirmed old theoretical predictions that binary systems formed with compact stars play a crucial role not only for cosmology and nuclear astrophysics [1]. As a byproduct of these and subsequent observations, it is now clear that neutron-star mergers can be a competitive site for the production of half of the elements heavier than iron in the Universe following a sequence of fast neutron capture reactions known as the r process. In this article we discuss an effect which has been so far neglected in calculations of r-process nucleosynthesis in neutron star mergers. We show that the corrections due to the neutron environment even at relatively small neutron densities, within the bounds of numerical hydrodynamical simulations of neutron star mergers and after the onset of the r process, are non-negligible and need to be taken into account to accurately describe the elemental abundance as determined by observations.

中文翻译：

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核介质对中子星合并过程中中子俘获反应的影响

引力波的发现证实了古老的理论预测，即由紧凑恒星形成的双星系统不仅对宇宙学和核天体物理学起着至关重要的作用[1]。作为这些以及随后观察的副产品，现在很明显，在一系列快速的中子俘获反应（称为r过程）之后，中子星合并可能是一个竞争性场所，在宇宙中产生比铁重一半的元素。 。在本文中，我们讨论了迄今为止在中子星合并中r过程核合成的计算中被忽略的效应。我们证明，即使在相对较小的中子密度下，在中子星合并的数值流体动力学模拟的范围内以及在r过程开始之后，由于中子环境引起的修正，