论文标题
用卫星运动学跟踪暗物质光环和星系中心的恒星速度分散
Tracing Dark Matter Halos with Satellite Kinematics and the Central Stellar Velocity Dispersion of Galaxies
论文作者
论文摘要
已经提出，星系的中央恒星速度分散可以直接追踪暗物质光环质量。我们使用Sloan Digital Sky Sumpery Data Release 12中的淡淡的卫星星系包围的孤立星系的完整光谱样本测试了这一假设。我们应用了一个与预计的链接长度$ΔD<100 $ kpc和radial速度的速度和径向速度链接长度$ΔV<1000 $ KM S $ KM S $ KM S $ km s $ km s $^wossplasty的样本的朋友;我们的样本包括2807个孤立的星系，带有3417个卫星星系为0.01美元<z <0.14 $。我们根据主要星系颜色将样品分为两组：红色和蓝色的主要星系分开为$（g-r）_ {0} = 0.85 $。主要星系的中央恒星速度分散体与同一星系的亮度和恒星质量成正比。根据原发星系的中央速度分散堆叠样品，我们得出了其卫星星系的速度分散体，这些速度分散体追踪主要星系的暗物质晕质量。卫星星系的系统速度散布显示与红色和蓝色样品的主要星系的中央速度分散相关。特别是，对于红色主系统，关系的斜率与1相同。这种紧密的关系表明，星系的中央恒星速度分散确实是暗物质光环质量的有效且健壮的示踪剂。我们提供了中央恒星速度分散与暗物质光环质量之间的经验关系。
It has been suggested that the central stellar velocity dispersion of galaxies can trace dark matter halo mass directly. We test this hypothesis using a complete spectroscopic sample of isolated galaxies surrounded by faint satellite galaxies from the Sloan Digital Sky Survey Data Release 12. We apply a friends-of-friends algorithm with projected linking length $ΔD < 100$ kpc and radial velocity linking length $ΔV < 1000$ km s$^{-1}$ to construct our sample. Our sample includes 2807 isolated galaxies with 3417 satellite galaxies at $0.01 < z < 0.14$. We divide the sample into two groups based on the primary galaxy color: red and blue primary galaxies separated at $(g-r)_{0} = 0.85$. The central stellar velocity dispersions of the primary galaxies are proportional to the luminosities and stellar masses of the same galaxies. Stacking the sample based on the central velocity dispersion of the primary galaxies, we derive the velocity dispersions of their satellite galaxies, which trace the dark matter halo mass of the primary galaxies. The system velocity dispersion of the satellite galaxies shows a remarkably tight correlation with the central velocity dispersion of the primary galaxies for both red and blue samples. In particular, the slope of the relation is identical to 1 for red primary systems. This tight relation suggests that the central stellar velocity dispersion of galaxies is indeed an efficient and robust tracer for dark matter halo mass. We provide empirical relations between the central stellar velocity dispersion and the dark matter halo mass.
