Star clusters appear to be the ideal environment for the assembly of neutron star–neutron star (NS–NS) and black hole–neutron star (BH–NS) binaries. These binaries are among the most interesting astrophysical objects, being potential sources of gravitational waves (GWs) and gamma-ray bursts. We use for the first time high-precision N-body simulations of young massive and open clusters to study the origin and dynamical evolution of NSs, within clusters with different initial masses, metallicities, primordial binary fractions, and prescriptions for the compact object natal kicks at birth. We find that the radial profile of NSs is shaped by the BH content of the cluster, which partially quenches the NS segregation due to the BH-burning process. This leaves most of the NSs out of the densest cluster regions, where NS–NS and BH–NS binaries could potentially form. Due to a large velocity kick that they receive at birth, most of the NSs escape the host clusters, with the bulk of their retained population made up of NSs of ∼1.3 coming from the electron-capture supernova process. The details of the primordial binary fraction and pairing can smear out this trend. Finally, we find that a subset of our models produce NS–NS mergers, leading to a rate of ∼0.01–0.1 in the local universe, and compute an upper limit of ∼3נ10⁻²–3נ10⁻³ for the BH–NS merger rate. Our estimates are several orders of magnitude smaller than the current empirical merger rate from LIGO/Virgo, in agreement with the recent rate estimates for old globular clusters.

星团似乎是中子星-中子星（NS-NS）和黑洞-中子星（BH-NS）双星组装的理想环境。这些双星是最有趣的天体物理天体之一，是引力波 (GW) 和伽马射线爆发的潜在来源。我们第一次使用高精度N年轻的大质量和疏散星团的体模拟，以研究具有不同初始质量、金属丰度、原始二元分数的星团内 NS 的起源和动力学演化，以及出生时紧凑物体本命踢的处方。我们发现 NSs 的径向轮廓是由簇的 BH 含量形成的，这部分地抑制了由于 BH 燃烧过程导致的 NS 分离。这使得大多数 NS 不在最密集的集群区域之外，在那里可能会形成 NS-NS 和 BH-NS 二进制文件。由于它们在出生时受到很大的速度冲击，大多数 NSs 逃离了宿主集群，它们的大部分保留种群由大约 1.3 的 NSs 组成来自电子捕获超新星过程。原始二元分数和配对的细节可以抹掉这种趋势。最后，我们发现我们的模型的一个子集产生了 NS-NS 合并，导致本地宇宙中的比率为 ~0.01-0.1 ，并计算了 BH-NS 合并的上限为 ~3 נ10 ^-2 -3נ10 ^-3 速度。我们的估计比目前 LIGO/Virgo 的经验合并率小几个数量级，这与最近对旧球状星团的速率估计一致。