Constraints on the Distribution of Dark Matter within the Milky Way

人们普遍认为，我们银河系的大部分质量都存在于 一个或多个看不见的“暗”成分。 在没有直接 探测，暗物质的分布可以通过 观察它对适当选择的示踪剂的引力效应， 银河系的势能 观察两个不同的 造父变星和K矮星的示踪剂，将被用来 （a）从太阳到太阳中心的距离 星系，（B）闭合轨道偏离轴对称 在太阳附近经过，以及（c）盘的质量表面密度 银河系在太阳的位置。 偏离 通过寻找新的造父变星， 向银河经度l = 60度，补充了最近的一个 向l = 300度方向成功进行了搜索。 后续行动 将在近红外1.2、1.6和1.8处获得测光结果。 2.2微米，其中星际灭绝的影响是 大幅减少。

It is widely believed that most of the mass in our Galaxy lies in one or more unseen "dark" components. In the absence of direct detection, the distribution of dark matter can be mapped by observing its gravitational effects on suitably chosen tracers of the Milky Way's potential energy. Observations of two different tracers, Cepheid variable stars and K dwarfs, will be used to determine (a) the distance from the Sun to the center of the Galaxy, (b) the deviation from axisymmetry of the closed orbits passing near the Sun, and (c) the mass surface density of the disk of the Galaxy at the Sun's position. The deviation from axisymmetry will be obtained by way of a search for new Cepheids toward galactic longitude l = 60 degrees, complementing a recent successful search carried out toward l = 300 degrees. Followup photometry will be obtained in the near infrared at 1.2, 1.6, and 2.2 microns, where the effects of interstellar extinction are substantially reduced.