论文标题
探索带有的银河系磁盘和外磁盘的子结构
Exploring the pertubed Milky Way disk and the substructures of the outer disk
论文作者
论文摘要
最近在太阳能街区$ z-v_z $相位平面中发现的螺旋功能的发现，这意味着银河磁盘受到大约亿年前经过的矮星银河的显着影响。使用429,500张Lamost K巨人星星，我们表明螺旋特征不仅在太阳附近退出。它也延伸到距银河中心约15 kpc，然后消失在此半径之外。此外，我们发现，当在各种半乳突中以$ z-v_z $平面中的位置的螺旋特征重新映射到$ r-z $平面时，螺旋可以很好地解释观察到的不对称速度子结构。这证明了相螺旋特征与上一项工作以及这项工作中发现的批量运动相同。测试粒子模拟和N体模拟表明，几亿年前与矮星系的相遇将引起银河系磁盘的扰动。此外，我们发现SGR DSPH的最后影响也会导致耀斑。由于遭遇，重力扰动印有磁盘恒星在大范围的半径上的分布函数。
The recent discovery of a spiral feature in $Z-V_Z$ phase plane in the solar neighborhood implies that the Galactic disk has been remarkably affected by a dwarf galaxy passing through it some hundreds of millions of years ago. Using 429,500 LAMOST K giants stars, we show that the spiral feature exits not only in the solar vicinity; it also extends to about 15 kpc from the Galactic center, and then disappears beyond this radius. Moreover, we find that when the spiral features in a plot of $V_ϕ$ as a function of position in the $Z-V_Z$ plane, at various Galactocentric radii, are re-mapped to $R-Z$ plane, the spiral can explain well the observed asymmetric velocity substructures. This is evidence that the phase spiral features are the same as the bulk motions found in previous as well as this work. Test-particle simulations and N-body simulations show that an encounter with a dwarf galaxy a few hundred million years ago will induce a perturbation in the Galactic disk. In addition, we find that the last impact of Sgr dSph can also contribute to the flare. As a consequence of the encounter, the distribution function of disk stars at a large range of radii is imprinted by the gravitational perturbation.
