论文标题
GAIA DR3适当动作的新恒星速度子结构
New stellar velocity substructures from Gaia DR3 proper motions
论文作者
论文摘要
预计并已证明局部恒星运动包括银河系过去动态进化的签名。这些通常分为椎间盘，该碟片显示螺旋臂和条的动态效应以及恒星的光环，结构被认为是过去合并的碎屑。我们使用Gaia数据版本3选择这些人群的大型样本，而不将它们限制为径向速度的来源。我们对这些样品应用惩罚的最大似然方法，以确定笛卡尔$（u，v，w）$或球形$（v_r，v_r，v_ ϕ，v_θ）$坐标中的完整3D速度分布。我们发现，光盘总体由四个移动组主导，还检测一个新的移动组，以$（u，v）=（-10，-15）$ km s $^{ - 1} $，我们称为MMH-0。对于恒星光环，我们将积分分量分离为横向速度和颜色刻度图。在此组件中，我们发现几个已知的结构被认为是由过去的合并引起的，尤其是$（v_r，v_Dcart，v_θ）=（-150，-300，-100）$ km s $ s $^{ - 1} $似乎比以前声称的更为突出。此外，我们还确定了$（v_r，v_ϕ，v_θ）附近的两个新结构=（225，25，325）$ km s $ s $^{ - 1} $和$（0，150，-125）$ s $ s $ s $ s $^{ - 1} $，我们分别称为MMMH-1和MMH-1和MMH-1和MMH-2-2。这些结果为局部恒星动作提供了新的见解，并显示了不限于具有测量速度速度的恒星的样品的潜力，这是提供大量恒星样本的关键，这是未来研究所必需的。
Local stellar motions are expected, and have been shown, to include signatures of the Galaxy's past dynamical evolution. These are typically divided into the disc, which shows the dynamical effects of spiral arms and the bar, and the stellar halo, with structures thought to be debris from past mergers. We use Gaia Data Release 3 to select large samples of these populations without limiting them to sources with radial velocities. We apply a penalised maximum likelihood method to these samples to determine the full 3D velocity distribution in Cartesian $(U, V, W)$ or spherical $(v_r, v_ϕ, v_θ)$ coordinates. We find that the disc population is dominated by four moving groups and also detect a new moving group at $(U, V) = (-10, -15)$ km s$^{-1}$ which we call MMH-0. For the stellar halo, we isolate the accreted component with cuts in transverse velocity and the colour-magnitude diagram. In this component we find several known structures believed to be caused by past mergers, particularly one around $(v_r, v_ϕ, v_θ) = (-150, -300, -100)$ km s$^{-1}$ appears more prominent than previously claimed. Furthermore we also identify two new structures near $(v_r, v_ϕ, v_θ) = (225, 25, 325)$ km s$^{-1}$ and $(0, 150, -125)$ km s$^{-1}$ which we refer to as MMH-1 and MMH-2 respectively. These results give new insights into local stellar motions and shows the potential of using samples that are not limited to stars with measured line-of-sight velocities, which is key to providing large samples of stars, necessary for future studies.
