标题： 中子星合并喷发物中的核合成 显示英文标题

标题： Nucleosynthesis in the Ejecta of Neutron Star Mergers

摘要： 金、铂或铀等重元素是在r过程（快中子俘获过程）中产生的，而该过程需要中子丰富的爆炸环境。中子星合并被认为是r过程发生的一个有希望的候选场所。 它们表现出三种不同的物质抛射通道，满足这些条件：由于潮汐扭矩引起的动态抛射物、中微子驱动风以及吸积盘蒸发物质。 我们首次研究了中微子驱动风的综合核合成，这是来自一颗超大质量中子星合并的中微子驱动风。 最近的流体力学模拟得到的轨迹被分为四个不同的角度区域，并通过反应网络进行事后处理。 我们发现电子分数大约在$Y_e \approx 0.1 - 0.4$周围变化，但其分布因抛射的角度不同而异。 因此，风抛射物不会经历稳定的r过程，而是根据角度范围具有不同的核合成产率。 与动态抛射物相比，较少的中子丰富物质被解绑，但在中微子驱动风中的较轻重元素（$A \lesssim 130$）的生产可以补充动态抛射物的强r过程。 显示英文摘要

摘要： Heavy elements like gold, platinum or uranium are produced in the r-process, which needs neutron-rich and explosive environments. Neutron star mergers are a promising candidate for an r-process site. They exhibit three different channels for matter ejection fulfilling these conditions: dynamic ejecta due to tidal torques, neutrino-driven winds and evaporating matter from the accretion disk. We present a first study of the integrated nucleosynthesis for a neutrino-driven wind from a neutron star merger with a hyper-massive neutron star. Trajectories from a recent hydrodynamical simulation are divided into four different angle regions and post-processed with a reaction network. We find that the electron fraction varies around $Y_e \approx 0.1 - 0.4$, but its distribution differs for every angle of ejection. Hence, the wind ejecta do not undergo a robust r-process, but rather possess distinct nucleosynthesis yields depending on the angle range. Compared to the dynamic ejecta, a smaller amount of neutron-rich matter gets unbound, but the production of lighter heavy elements with $A \lesssim 130$ in the neutrino-driven wind can complement the strong r-process of the dynamic ejecta.