标题： 轴子及其在星系晕中的分布 显示英文标题

标题： Axions and their Distribution in Galactic Halos

摘要： 轴子物理被简要回顾。 实验室搜索、天体物理学和宇宙学的限制要求轴子质量处于$10^{-6} \lesssim m_a < 3\cdot 10^{-3}$eV 的范围内。 在这个范围的低端，轴子是宇宙冷暗物质的全部或主要组成部分。 轴子以及任何其他冷暗物质粒子在我们星系晚期的流入，在其晕中产生了流和焦散结构。 外部焦散结构是拓扑球面，而内部焦散结构则是环状。 星系晕形成的自相似模型预测焦散环半径$a_n$遵循近似的定律$a_n \sim 1/n$。 在这条规律在对32个扩展且测量良好的外部星系旋转曲线的统计研究以及银河系旋转曲线中尖锐上升现象的存在和分布中得到了验证。 此外，银河系平面的IRAS图中的一个三角特征与环焦散结构在重子物质上的印记一致，并且其位置与离我们最近的旋转曲线的上升部分相吻合。 这些观测表明我们附近的暗物质主要由单一的流组成。 给出了该流密度和速度矢量的估计值。 显示英文摘要

摘要： Axion physics is briefly reviewed. Constraints from laboratory searches, astrophysics and cosmology require the axion mass to be in the range $10^{-6} \lesssim m_a < 3\cdot 10^{-3}$eV. Near the lower end of this range, axions are all or a major component of the cold dark matter of the universe. The late infall of axions, and of any other cold dark matter particles, onto our galaxy produces streams and caustics in its halo. The outer caustics are topological spheres whereas the inner caustics are rings. The self-similar model of galactic halo formation predicts that the caustic ring radii $a_n$ obey the approximate law $a_n \sim 1/n$. Evidence for this law has been found in a statistical study of 32 extended and well-measured external galactic rotation curves, and in the existence and distribution of sharp rises in the Milky Way rotation curve. Moreover, a triangular feature in the IRAS map of the Galactic plane is consistent with the imprint of a ring caustic upon the baryonic matter. Its position coincides with a rise in the rotation curve, the one nearest to us. These observations imply that the dark matter in our neighborhood is dominated by a single flow. Estimates of that flow's density and velocity vector are given.