论文标题
射手座矮人球形星系中恒星的多重性统计：与银河系的比较
Multiplicity Statistics of Stars in the Sagittarius Dwarf Spheroidal Galaxy: Comparison to the Milky Way
论文作者
论文摘要
我们使用来自Apache点观测值银河进化实验（Apogee）的时间分辨光谱来检查249颗恒星中径向速度（RV）变化的分布，而Hayes等人（2020）被Hayes等人（2020）鉴定为Sagittarius（SGR）Dwarf Spheroidal（DSPH）的成员。我们选择具有恒星参数（$ log（g）$，$ t_ {eff} $和$ [fe/h] $）的星星（$ log（g）$，$ t_ {fe/h] $），类似于Sagittarius成员的k-d dimension 3。我们发现，我们发现SGR DSPH星体中RV Shifts的形状与SGR DSPH的分布形状相似，这些星星与该型号相似。 DSPH较大，$ \ sim 2 $。在排除了有关这种差异的其他解释之后，我们得出结论，SGR DSPH中近距离二进制的比例本质上高于MW。我们讨论了该结果对导致矮球和螺旋星系中紧密二进制的物理过程的含义。
We use time-resolved spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) to examine the distribution of radial velocity (RV) variations in 249 stars identified as members of the Sagittarius (Sgr) dwarf spheroidal (dSph) galaxy by Hayes et al (2020). We select Milky Way (MW) stars that have stellar parameters ($log(g)$, $T_{eff}$, and $[Fe/H]$) similar to those of the Sagittarius members by means of a k-d tree of dimension 3. We find that the shape of the distribution of RV shifts in Sgr dSph stars is similar to that measured in their MW analogs, but the total fraction of RV variable stars in the Sgr dSph is larger by a factor of $\sim 2$. After ruling out other explanations for this difference, we conclude that the fraction of close binaries in the Sgr dSph is intrinsically higher than in the MW. We discuss the implications of this result for the physical processes leading to the formation of close binaries in dwarf spheroidal and spiral galaxies.
