论文标题
星系的平衡模型的残差揭示了太阳邻居的不平衡状态
Residuals of an Equilibrium Model for the Galaxy Reveal a State of Disequilibrium in the Solar Neighborhood
论文作者
论文摘要
我们同时使用{\ it gaia} dr2径向速度目录来对太阳附近的巨星的重力和相空间分布函数（DF）进行建模。我们假设银河系处于平衡状态，并且对磁盘的自旋轴和银河中平面均具有对称性。潜力被视为名义上代表气盘，恒星磁盘，凸起和暗物质光环的贡献的术语之和。我们用于巨人的DF模型包括两个组件，以解释薄磁盘恒星的混合物。每个组件的DF由能量，自旋角动量和垂直能的分析函数根据牛仔裤定理描述。我们提出了对太阳的$ \ sim 2 \，{\ rm kpc} $内的径向和垂直力的模型预测，突出了太阳邻域中的旋转曲线和垂直力剖面。最后，我们在$ r-Z $和$ z-v_z $ planes以及$ z-v_z $ plane中平均径向和方位角速度的地图上显示了恒星计数的残差。使用我们的模型来发挥潜力，我们还检查了动作频角坐标中的星数残差。这些地图中的{\ it Gaia}相螺旋，速度拱，一些已知的移动组和弯曲模式出现得出明确的特征。
We simultaneously model the gravitational potential and phase space distribution function (DF) of giant stars near the Sun using the {\it Gaia} DR2 radial velocity catalog. We assume that the Galaxy is in equilibrium and is symmetric about both the spin axis of the disk and the Galactic midplane. The potential is taken as a sum of terms that nominally represent contributions from the gas disk, stellar disk, bulge, and dark matter halo. Our DF model for the giants comprise two components to account for a mix of thin and thick disk stars. The DF for each component is described by an analytic function of the energy, the spin angular momentum, and the vertical energy, in accord with Jeans theorem. We present model predictions for the radial and vertical forces within $\sim 2\,{\rm kpc}$ of the Sun, highlighting the rotation curve and vertical force profile in the Solar Neighbourhood. Finally, we show residuals for star counts in the $R-z$ and $z-v_z$ planes as well as maps of the mean radial and azimuthal velocities in the $z-v_z$ plane. Using our model for the potential, we also examine the star count residuals in action-frequency-angle coordinates. The {\it Gaia} phase spirals, velocity arches, some of the known moving groups and bending modes appear as well-defined features in these maps.
