银晕中中子星环境的演化：对暗物质吸积的启示
Evolution of Neutron Star Environment in the Galactic Halo : Implications for Dark Matter Accretion
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中文总结 AI 辅助
该研究通过N体模拟和沃罗诺伊镶嵌方法，发现银晕中子星周围暗物质子结构动力学可使中子星内暗物质质量较基线预期增强约2倍，但仍无法解释相关估计的数量级差异。
中文摘要 AI 辅助
中子星（NS）是暗物质（DM）的间接探测探针之一，已知暗物质的存在会影响中子星的可观测性质。针对含暗物质中子星的各种物态方程进行的理论计算，得出中子星内暗物质质量约为10⁻²倍太阳质量（M☉）的估计。另一方面，对太阳系附近区域内中子星在其寿命期间吸积的暗物质总量进行的简化估计，得出该数值约为10⁻¹⁴倍太阳质量。已有多项研究从理论层面解释了导致暗物质吸积量高于平滑球对称吸积预期的机制，以解决这一不一致问题。本研究旨在评估银晕中动态暗物质环境密度的作用，以解释暗物质吸积可能出现的增强效应。我们采用高分辨率N体模拟和沃罗诺伊镶嵌（Voronoi tessellation）方法，在具有统计代表性的银河系类似样本中，计算假设中子星位置周围的局域暗物质密度。我们推断，子结构的动力学可能使中子星内的暗物质质量相较于球对称吸积的基线预期增强约2倍。因此，环境效应无法解释基于物态方程和吸积得出的、含暗物质中子星内暗物质含量之间的数量级差异。
英文摘要
Neutron stars (NS) are one of the indirect detection probes for dark matter (DM). The presence of DM is known to affect the observable properties of NS. Theoretical calculations for various equations of state of a DM admixed NS lead to estimates of the DM mass in a NS of the order of $10^{-2} M_{\odot}$. On the other hand, simplistic estimates of the amount of DM that is accreted on to the NS in the Solar neighborhood, over its age, suggest that this number is of the order $10^{-14} M_{\odot}$. Various studies have addressed this non-agreement theoretically by explaining the mechanisms leading to higher fraction than expected from smooth spherically symmetric accretion. In this work, we attempt to assess the role of the dynamic DM environmental density in the Galactic halo to explain possible enhancement in DM accretion. We consider a high resolution N-body simulation and method of Voronoi tessellation to calculate local DM density around putative NS locations in a statistically representative sample of Milky Way analogues. We infer that the dynamics of substructure may enhance the DM mass in NS by about a factor 2 as compared to the baseline, spherically symmetric expectation. Environmental effects therefore cannot explain the orders of magnitude discrepancy between equation of state and accretion based estimates of DM admixed in NS.
