论文标题
在盖亚（Gaia）发现的附近恒星光环中的两个子结构和狂欢
Two substructures in the nearby stellar halo found in Gaia and RAVE
论文作者
论文摘要
我们使用第二个GAIA数据释放（GAIA DR2），并结合了狂欢光谱调查，以识别附近恒星光环中的子结构。我们从运动和化学上选择3,845颗光晕恒星，并确定其在能量和角动量空间中的密度分布。为了从过度繁殖中选择子结构，我们重新填充了速度并估算其重要性。确定了两个具有统计学意义的子结构，即GR-1和GR-2。 GR-1具有较高的结合能和小$ Z $ - 角动量。 GR-2是金属丰富但逆行的。它们都是新的子结构，可能是矮星系的积聚碎片。
We use the second Gaia data release (Gaia DR2), combined with RAVE spectroscopic surveys, to identify the substructures in the nearby stellar halo. We select 3,845 halo stars kinematically and chemically, and determine their density distribution in energy and angular momentum space. To select the substructures from overdensities, we reshuffle the velocities and estimate their significance. Two statistically significant substructures, GR-1 and GR-2, are identified. GR-1 has a high binding energy and small $z$-angular momentum. GR-2 is metal-rich but retrograde. They are both new substructure, and may be accretion debris of dwarf galaxies.
