论文标题
Gaia DR3在太阳附近的恒星光环中的动力下结构视图
The Gaia DR3 view of dynamical substructure in the stellar halo near the Sun
论文作者
论文摘要
预计过去合并事件的碎屑在某种程度上是在太阳附近散布的恒星光环。我们旨在使用GAIA DR3数据来识别和表征此类合并碎片，并从Lamost LRS和Apogee中补充了金属性和化学丰度信息，用于距离太阳2.5 kpc以内的光晕恒星。我们利用基于单个链接的聚类算法来识别运动空间积分中的过度密度，这可能是由于合并碎片引起的。与金属性信息和化学丰度相结合，我们表征了这些具有统计学意义的过度固定。我们发现局部恒星光环包含7个主要动力组，其中一些原位和一些积聚的起源，其中大多数已经知道。我们报告了一个新的子结构的发现，我们将其命名为ED-1。此外，我们找到了11个独立的较小团块的证据，其中5个是新的：ED-2、3、4、5和6通常是动态紧密的，描绘了一小范围的金属范围，并且它们的丰度在可用时以及它们在运动空间中的位置，暗示了一个积聚的起源。局部光环包含一定数量的基结构，包括原位和积聚的起源。
The debris from past merger events is expected and, to some extent, known to populate the stellar halo near the Sun. We aim to identify and characterise such merger debris using Gaia DR3 data supplemented by metallicity and chemical abundance information from LAMOST LRS and APOGEE for halo stars within 2.5 kpc from the Sun. We utilise a single linkage-based clustering algorithm to identify over-densities in Integrals of Motion space that could be due to merger debris. Combined with metallicity information and chemical abundances, we characterise these statistically significant over-densities. We find that the local stellar halo contains 7 main dynamical groups, some of in-situ and some of accreted origin, most of which are already known. We report the discovery of a new substructure, which we name ED-1. In addition, we find evidence for 11 independent smaller clumps, 5 of which are new: ED-2, 3, 4, 5 and 6 are typically rather tight dynamically, depict a small range of metallicities, and their abundances when available, as well as their location in Integrals of Motion space, suggest an accreted origin. The local halo contains an important amount of substructure, of both in-situ and accreted origin.
