论文标题
Gaia DR3径向动作显示的圆盘中的螺旋状特征
Spiral-like features in the disc revealed by Gaia DR3 radial actions
论文作者
论文摘要
我们旨在探索新的Gaia DR3星体测量结果以在银河盘中找到结构的作用。我们根据银河系的轴对称模型来计算Gaia DR3恒星的动作和轨道参数。使用Gaia DR3光度数据，我们选择了一个以更好的天体统计为控制样本的巨人恒星的子集。径向作用J_R的百分位图显示了螺旋状形状结构。我们发现一个高的J_R区域的含量为1 kpc的r〜10.5 kpc，以及三个弧形的区域，以圆形轨道为主导。我们还确定了巨大人口过度的螺旋臂。我们发现与Scutum-Sagittarius螺旋臂的文献中的文献达成了很好的协议。在较大的半径上，低J_R结构在负X处跟踪局部臂，而对于珀尔修斯组，协议仅限于x <2 kpc区域，在文献方面具有更大的负纵向的位置。我们在〜10.5 kpc的半半径上检测到一个高J_R区域，与外部lindblad共振位置的某些估计相一致。我们得出的结论是，在几个地方，旧恒星动力学的模式是一致的，而年轻人群追踪的螺旋臂的空间分布，移动组的潜在贡献很小。
We aim to explore the actions of the new Gaia DR3 astrometry to find structures in the Galactic disc. We compute the actions and the orbital parameters of the Gaia DR3 stars with full astrometry and velocities assuming an axisymmetric model for the Milky Way. Using Gaia DR3 photometric data, we select a subset of giants stars with better astrometry as control sample. The maps of the percentiles of the radial action J_R reveal spiral-like shape structures. We find a high J_R region centered at R~10.5 kpc of 1 kpc width, as well as three arc-shape regions dominated by circular orbits at inner radii. We also identify the spiral arms in the overdensities of the giant population. We find a good agreement with the literature in the innermost region for the Scutum-Sagittarius spiral arms. At larger radii, the low J_R structure tracks the Local arm at negative X, while for the Perseus arm the agreement is restricted to the X<2 kpc region, with a displacement with respect to the literature at more negative longitudes. We detect a high J_R area at a Galactocentric radii of ~10.5 kpc, consistent with some estimations of the Outer Lindblad Resonance location. We conclude that the pattern in the dynamics of the old stars is consistent in several places with spatial distribution of the spiral arms traced by young populations, with small potential contributions from the moving groups.
