发表机构
MIT Kavli Institute for Astrophysics and Space Research; Kavli Institute for Particle Astrophysics and Cosmology, Stanford University; Department of Physics, Stanford University; SLAC National Accelerator Laboratory; The Observatories of the Carnegie Institution for Science; Department of Astrophysical Sciences, Princeton University（麻省理工学院卡弗里天体物理学与空间研究研究所; 斯坦福大学卡弗里粒子天体物理学与宇宙学研究所; 斯坦福大学物理系; 斯坦福直线加速器国家实验室; 卡内基科学机构天文台; 普林斯顿大学天体物理科学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用galacticus模型模拟银河系暗子晕，预测24条球状星团星流遭遇子晕的情况，发现Jet等星流最敏感，可作为探测低质量暗物质子晕的有效探测器。
AI 中文摘要
低质量暗物质子晕的丰度和性质可以通过测量星流的密度和速度结构来推断，从而检验暗物质的物理模型。哪些星流最有希望成为暗物质探测器，它们又会遇到哪些子晕？我们使用半解析模型galacticus模拟银河系的暗子晕，包括在银盘影响下的潮汐剥离。通过推导出与当前观测最匹配的星流初始条件，我们预测了银河系周围24个球状星团星流的子晕遭遇。在其生命周期内，预测受到扰动最严重的10条星流各自会经历约2至12次显著的子晕遭遇，速度冲量$v_\mathrm{kick} > 0.1$ km s$^{-1}$。Jet、AAU、GD-1和Palomar 5位居前列，其中Jet遭遇的子晕数量是任何其他星流的两倍。遭遇星流的子晕已被潮汐剥离至其峰值质量的1%至20%，且比先前研究假设的致密两倍。对星流进行亚km s$^{-1}$精度的光谱巡天，可以揭示低于星系形成阈值的暗子晕的影响。预测到达银河系内部的低质量子晕的丰度和离散度，仍是连接星流与暗物质模型的主要不确定性。
英文摘要
The abundance and properties of low-mass dark matter subhalos can be inferred by measuring the density and velocity structure of stellar streams, testing physical models of dark matter. Which streams make the most promising dark matter detectors, and which subhalos would they encounter? We use the semi-analytic model galacticus to simulate the Milky Way's dark subhalos, including tidal stripping under the influence of the galactic disk. Deriving stream initial conditions that best match present-day observations, we forecast subhalo encounters for 24 globular cluster streams around the Milky Way. Over their lifetimes, the 10 most perturbed streams are predicted to each experience $\approx 2$-$12$ significant subhalo encounters with velocity kicks $v_\mathrm{kick} > 0.1$ km s$^{-1}$. Jet, AAU, GD-1, and Palomar 5 lead the list, with Jet encountering twice the subhalos of any other stream. The subhalos that encounter streams have been tidally stripped to $1$-$20\%$ of their peak mass and are twice as compact as previous works have assumed. A spectroscopic survey of streams with sub-km s$^{-1}$ precision could reveal the influence of dark subhalos below the threshold of galaxy formation. Predicting the abundance and scatter of low-mass subhalos that reach the inner galaxy remains a dominant uncertainty in connecting stellar streams to models of dark matter.
Comments29 pages, 18 figures;
