Milky Way Rotation: Deviations from Circular Motion and the

谢克特博士将对造父变星和碳星进行观测，以确定银河系潜力的形状。在这两种情况下，光度测量法将得出到恒星的距离，而光谱学将得出速度。来自造父变星的数据也将被用来确定太阳到银河系中心的距离。事实证明，很难确定盘状结构、凸起结构和暗物质对星系总质量的相对贡献。更好地理解暗物质和发光物质在星系中的相对重要性，是理解星系如何形成和演化的先决条件。在银河系中，人们可以测量特定质量示踪物的位置和速度的所有三个分量。我们对银河系质量分布的了解可以用来了解其他星系的结构。谢克特博士的研究解决了银河系结构中的两个基本问题--银河系中太阳的轨道在多大程度上是非圆形的，以及太阳到银河系中心的距离。

Dr. Schechter will obtain observations of Cepheid variable stars and carbon stars to determine the shape of the potential of our Galaxy. In both cases photometry will yield distances to the stars while spectroscopy will yield velocities. The data from the Cepheids will also be used to determine the distance from the Sun to the center of our Galaxy. It has proven difficult to determine the relative contributions of a disk, a bulge, and dark matter to the total masses of galaxies. A better understanding of the relative importance of dark and luminous matter in a galaxy is a prerequisite to understanding how galaxies form and evolve. In the Milky Way galaxy one can measure all three components of position and velocity for specific tracers of mass. Our knowledge of the mass distribution in our Galaxy can then be applied to understanding the structure of other galaxies. Dr. Schechter's research addresses two of the fundamental problems in galactic structure -- the degree to which orbits are non- circular at the distance of the Sun in our Galaxy and the distance of the Sun to the center of our Galaxy.