Observations Constraining the Relative Masses of the Disk, Bulge and Halo of the Milky Way

在华盛顿卡内基研究所的威尔逊山天文台和拉斯坎帕纳斯天文台，谢克特博士正在进行一项观测研究项目，该项目由三个独立但相关的组成部分组成，所有这些部分都将有助于建立银河系质量的三维模型。该项目的重点是使用三种不同的质量示踪剂来确定圆盘、凸起和光晕对银河系质量的相对贡献。事实证明，要确定圆盘、凸起和暗晕对外部星系总质量的相对贡献尤其困难。更好地理解星系中暗物质和发光物质的相对重要性是理解星系如何形成的先决条件。谢克特博士研究的前提是，投影效应使得构建外部星系质量的良好约束模型几乎不可能。然而，在银河系中，人们可以测量各种各样的质量示踪剂的位置和速度的所有三个组成部分。我们对银河系质量分布的了解可以用来理解其他星系的结构。

Dr. Schechter, at the Mount Wilson and Las Campanas Observatories of the Carnegie Institution of Washington, is conducting an observational research project which consists of three separate but related components, all of which will aid the construction of three dimensional models of the mass of the Milky Way Galaxy. The project focuses on using three different tracers of mass to determine the relative contributions to the mass of our Galaxy from the disk, the bulge, and the halo. It has proven especially difficult to determine the relative contributions of a disk, a bulge, and a dark halo to the total masses of external galaxies. A better understanding of the relative importance of dark and luminous matter in a galaxy is a prerequisite to understanding how galaxies formed. The premise underlying Dr. Schechter's research efforts is that projection effects make it virtually impossible to construct well constrained models of the mass for external galaxies. However, in the Milky Way one can measure all three components of position and velocity for a wide variety of tracers of mass. Our knowledge of the mass distribution in our Galaxy can then be applied to understanding the structure of other galaxies.