论文标题
年轻大型和开放集群中的中子星人的人口统计
Demographics of neutron stars in young massive and open clusters
论文作者
论文摘要
星形簇似乎是组装中子星星星（NS-NS）和黑孔 - 中子恒星（BH-NS）二进制的理想环境。这些二进制文件是最有趣的天体物理物体之一，是引力波（GWS）和伽马射线爆发的潜在来源。我们首次使用年轻大规模和开放群集的高精度N体模拟来研究NSS的起源和动力学演化，在具有不同初始质量，金属质量，原始二元分数以及出生时紧凑型物体踢的群集中。我们发现，NSS的径向曲线是由簇的BH含量塑造的，群集的BH含量部分由于BH燃烧过程而部分解散了NS隔离。这将大多数NS排除在最密集的簇区域，其中NS-NS和BH-NS二进制可能会形成。由于他们出生时会收到的速度踢，因此大多数NS逃脱了主机群集，其大部分保留人口由$ \ sim 1.3 $ m $ _ \ odot $组成，来自电子快速超级诺沃的流程。原始二元分数和配对的细节可以弄清楚这一趋势。最后，我们发现我们的一部分模型产生了NS-NS合并，导致$ \ sim 0.01 $ - $ 0.1 $ GPC $^{ - 3} $ yr $^{ - 1} $在本地宇宙中，并计算上$ \ sim 3 \ sim 3 \ sim 3 \ sim 10^\ sim times 10^{ - 2} $ 3 \ $ 3 \ $ 3 \ 3 \ 3^ - yr $^{ - 1} $用于BH-NS合并率。我们的估计值是比Ligo/处女座的当前经验合并率小的几个数量级，这与旧球状簇的最新估计相一致。
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 $\sim 1.3$ M$_\odot$ 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 $\sim 0.01$--$0.1$ Gpc$^{-3}$ yr$^{-1}$ in the local Universe, and compute an upper limit of $\sim 3\times 10^{-2}$--$3\times 10^{-3}$ Gpc$^{-3}$ yr$^{-1}$ 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.
