Gusts in the headwind: uncertainties in direct dark matter detection
Gusts in the headwind: uncertainties in direct dark matter detection
复制标题
逆风中的阵风：直接暗物质探测的不确定性
DOI：
10.1093/mnras/stac2447
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发表时间：
2023
影响因子：
4.8
通讯作者：
Hopkins, Philip F
中科院分区：
文献类型：
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作者：
Lawrence, Grace E;Duffy, Alan R;Blake, Chris A;Hopkins, Philip F
我们使用来自Latte FIRE-2模拟套件的高分辨率、流体力学、星系模拟来研究银河型模拟星系太阳圈周围亚采样区域暗物质的内在变化及其对直接暗物质探测的影响。这些模拟表明，重子背反应以及子结构的组装历史，对暗物质的空间和速度分布具有持久的影响。这些被认为是围绕太阳圈的暗物质风，可能会使对地球上直接探测实验的解释复杂化。我们发现，银心框架中的速度分布函数与基准标准晕模型中通常假定的Maxwell Boltzmann形式有很大的偏差，这表明存在高速子结构。通过引入一种新的数值积分技术，消除了对标准光晕模型的任何依赖，我们生成了单元素Ge和化合物碘化钠探测器的事件率预测，并探索了太阳圈周围暗物质的可变性如何影响年度调制信号预测。我们发现，这些速度子结构对事件率的解释贡献了额外的天体物理不确定性，尽管它们对汇总统计数据(如年度调制的峰值日)的影响通常很小。
We use high-resolution, hydrodynamic, galaxy simulations from the Latte suite of FIRE-2 simulations to investigate the inherent variation of dark matter in sub-sampled regions around the Solar Circle of a Milky Way-type analogue galaxy and its impact on direct dark matter detection. These simulations show that the baryonic back reaction, as well as the assembly history of substructures, has lasting impacts on the dark matter’s spatial and velocity distributions. These are experienced as ‘gusts’ of dark matter wind around the Solar Circle, potentially complicating interpretations of direct detection experiments on Earth. We find that the velocity distribution function in the galactocentric frame shows strong deviations from the Maxwell Boltzmann form typically assumed in the fiducial Standard Halo Model, indicating the presence of high-velocity substructures. By introducing a new numerical integration technique that removes any dependencies on the Standard Halo Model, we generate event-rate predictions for both single-element Germanium and compound Sodium Iodide detectors, and explore how the variability of dark matter around the Solar Circle influences annual modulation signal predictions. We find that these velocity substructures contribute additional astrophysical uncertainty to the interpretation of event rates, although their impact on summary statistics, such as the peak day of annual modulation, is generally low.