论文标题
通过蓝色的散乱将本地恒星光环及其暗物质密度连接到矮星系
Connecting the local stellar halo and its dark matter density to dwarf galaxies via blue stragglers
论文作者
论文摘要
GAIA HR图显示了高切向速度处的明显年轻恒星。使用简单的分析模型，我表明这些恒星可能是蓝色的散落者。一旦标准化为红色巨星，附近的光环蓝散散股的一部分为20％，并且非常接近矮星系中测量的阶段。在这种相似性的激励下，我适用于矮星系中蓝色散曲板推断出的蓝色散曲板的比例关系。对于银河系，Halo的平均恒星密度为3.4 x 10^-5 msun/pc^3，而暗物质密度〜0.006 msun/pc^3〜0.22 gev/cm^3在2 kpc的距离太阳的2 kpc内。这些值与文献中可用的其他确定相比有利，但基于独立的假设集。讨论了这种方法的一些考虑，最值得注意的是，在矮星系中看到的暗物质光环核心密度与恒星质量之间的相关性似乎也与附近的银河系光环有关。
The Gaia HR diagram shows the presence of apparently young stars at high tangential velocities. Using a simple analytical model I show that these stars are likely to be blue stragglers. Once normalized to red giant stars, the fraction of nearby halo blue stragglers is of order 20 percent, and remarkably close to that measured in dwarf galaxies. Motivated by this similarity, I apply to field blue stragglers scaling relations inferred from blue stragglers in dwarf galaxies. Doing this for the Milky Way halo returns an average stellar density of 3.4 x 10^-5 Msun/pc^3 and a dark matter density of ~0.006 Msun/pc^3 ~ 0.22 GeV/cm^3 within 2 kpc from the Sun. These values compare favourably to other determinations available in the literature, but are based on an independent set of assumptions. A few considerations of this methodology are discussed, most notably that the correlation between the dark matter halo core-density and stellar mass seen in dwarf galaxies seems to hold also for the nearby Milky Way halo.
