论文标题
在GD-1恒星流中检测强层高密度尖峰。缺乏暗物质Subhalos影响的证据？
Detection of Strong Epicyclic Density Spikes in the GD-1 Stellar Stream. An Absence of Evidence for the Influence of Dark Matter Subhalos?
论文作者
论文摘要
薄恒星流的密度变化可能会编码有关暗物质本质的重要信息。例如，如果暗物质聚集成大量的亚山洛斯，则这些遗物有望从动态冷的恒星流中散射恒星，这可能会导致这些结构中的可检测间隙。在这里，我们使用GAIA DR2星形统计，Pan-Starrs光度法重新检查GD-1流中的密度变化，并与CFHT/Espadons和VLT/Uves仪器一起测量的高精度径向速度，并与公共径向速度速度分解。我们表明，在纠正投影效果后，密度曲线表现出高对比度周期峰，分别为$ 2.64 \ pm0.18 $ kpc。提出了N体模拟，该模拟以光滑的银河系潜力以简单的飞行运动来重现这种引人注目的形态。我们还讨论了使用地面光度测量测量密度变化的可靠性，对于GD-1的特殊情况，我们突出了GAIA DR2目录中沿其轨道中存在的一些文物。似乎不需要大规模的深色subhalos来解释沿GD-1的密度集成。
The density variations in thin stellar streams may encode important information on the nature of the dark matter. For instance, if dark matter aggregates into massive sub-halos, these perturbers are expected to scatter stars out of dynamically cold stellar streams, possibly leading to detectable gaps in those structures. Here we re-examine the density variations in the GD-1 stream, using Gaia DR2 astrometry, Pan-STARRS photometry, together with high precision radial velocities measured with the CFHT/ESPaDOnS and VLT/UVES instruments and complemented with public radial velocity catalogs. We show that after correcting for projection effects, the density profile exhibits high contrast periodic peaks, separated by $2.64\pm0.18$ kpc. An N-body simulation is presented that reproduces this striking morphology with simple epicyclic motion in a smooth Galactic potential. We also discuss the reliability of measuring density variations using ground-based photometric surveys, and for the particular case of GD-1 we highlight some of the artifacts present in the Gaia DR2 catalog along its track. Massive dark subhalos do not appear to be required to explain the density clumping along GD-1.
