Efficient solution of the anisotropic spherically-aligned axisymmetric Jeans equations of stellar hydrodynamics for galactic dynamics
Michele Cappellari
备注：
19 pages, 12 figures, LaTeX. Accepted for publication in MNRAS. The method described in this paper is included in the JAM software package at https://purl.org/cappellari/software
I present a flexible solution for the axisymmetric Jeans equations of stellar hydrodynamics under the assumption of an anisotropic (three-integral) velocity ellipsoid aligned with the spherical polar coordinate system. I describe and test a robust and efficient algorithm for its numerical computation. I outline the evaluation of the intrinsic velocity moments and the projection of all first and second velocity moments, including both the line-of-sight velocities and the proper motions. This spherically-aligned Jeans Anisotropic Modelling (JAM_sph) method can describe in detail the photometry and kinematics of real galaxies. It allows for a spatially-varying anisotropy, or stellar mass-to-light ratios gradients, as well as for the inclusion of general dark matter distributions and supermassive black holes. The JAM_sph method complements my previously derived cylindrically-aligned JAM_cyl and spherical Jeans solutions, which I also summarize in this paper. Comparisons between results obtained with either JAM_sph or JAM_cyl can be used to asses the robustness of inferred dynamical quantities. As an illustration, I modelled the Atlas3D sample of 260 early-type galaxies with high-quality integral-field spectroscopy, using both methods. I found that they provide statistically indistinguishable total-density logarithmic slopes. This may explain the previously-reported success of the JAM method in recovering density profiles of real or simulated galaxies. A reference software implementation of JAM_sph is included in the publicly-available JAM software package.
Axisymmetric Jeans modelling systematically overestimates the circular speed in the inner Milky Way
Graduate School of Science and Engineering, Kagoshima University（鹿儿岛大学理工学研究科）；Graduate School of Science, Nagoya University（名古屋大学理学研究科）；Division of Science, National Astronomical Observatory of Japan（日本国立天文台理学区）
The GECKOS survey: Jeans anisotropic models of edge-on discs uncover the impact of dust and kinematic structures
European Southern Observatory（欧洲南方天文台）；The University of Sydney（悉尼大学）；University of New South Wales（新南威尔士大学）；University of Oxford（牛津大学）；Liverpool John Moores University（利物浦约翰摩尔斯大学）；Durham University（杜伦大学）；Universidad de La Laguna（拉帕尔马大学）；University of Vienna（维也纳大学）；University of Surrey（萨里大学）；Cardiff University（卡迪夫大学）；Swinburne University of Technology（斯威本科技大学）；University of Oklahoma（俄克拉荷马大学）；Macquarie University（麦考瑞大学）；Space Telescope Science Institute（太空望远镜科学研究所）
Physical Explanation for the Galaxy Distribution on the $(λ_{\rm R}, \varepsilon)$ and $(V/σ, \varepsilon)$ Diagrams or for the Limit on Orbital Anisotropy
Stellar Velocity Dispersion and Anisotropy of the Milky Way Inner Halo
我们使用MMT望远镜的一个新的径向速度样本测量了银河系6 < R < 30 kpc范围内恒星的速度色散的三个分量$σ_{R},σ_θ,σ_ϕ$。我们将我们的测量与以前公布的数据相结合，以便我们可以更精细地对恒星晕进行采样。我们使用极大似然统计方法来估计平均速度、分散度和协方差，仅假设速度呈正态分布。速度椭球的排列与球对称引力势一致。根据球面金斯方程，银河系的质量为M（<12 kpc）= $1.3\times10^{11}$ M $_{\odot}$，不确定度为40%。我们还发现了一个不连续的区域，15 < R < 25 kpc，在那里估计的速度色散和各向异性偏离其预期值，在很大程度上证实了其他人观察到的破裂。我们认为，这种打破各向异性的物理解释相干恒星速度结构的晕，如Sgr流。为了显著提高我们对晕运动学的理解，需要将径向速度与未来的盖亚自行相结合。
HSTPROMO Internal Proper Motion Kinematics of Dwarf Spheroidal Galaxies: II. Velocity Anisotropy and Dark Matter Cusp Slope of Sculptor
Institute for Astronomy, University of Edinburgh（爱丁堡大学天文研究所）；Space Telescope Science Institute（太空望远镜科学研究所）；Center for Astrophysical Sciences, The William H. Miller III Department of Physics & Astronomy, Johns Hopkins University（约翰斯·霍普金斯大学天体物理科学中心）；Dept. of Astronomy & Space Science, Kyung Hee University（庆熙大学天文与空间科学系）；Centre for Statistics, University of Edinburgh（爱丁堡大学统计中心）；Department of Physics and Astronomy, University of Utah（犹他大学物理与天文系）
