The Shape and Scale of Galactic Rotation from Cepheid Kinematics
The Shape and Scale of Galactic Rotation from Cepheid Kinematics
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DOI：
10.1086/300198
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发表时间：
1997-10
期刊：
影响因子：
--
通讯作者：
M. Metzger;J. Caldwell;P. Schechter
中科院分区：
文献类型：
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作者：
M. Metzger;J. Caldwell;P. Schechter
造父变星的目录是用来探测银河系盘的运动学。在l = 300°的方向上测量了八颗遥远的造父变星的径向速度;这些新的造父变星提供了一个特别好的约束，即到银河系中心R 0的距离。我们用轴对称旋转曲线和弱椭圆分量的旋转曲线来模拟圆盘，并找到了太阳附近椭圆度为0.043 ± 0.016的证据。利用这些模型，我们得到R 0 = 7.66 ± 0.32 kpc和vcirc = 237 ± 12 km s-1。到银河系中心的距离与最近从天琴座RR型变星分布中得到的结果一致，并且不利于大多数在太阳轨道上具有大椭圆率的模型。
A catalog of Cepheid variables is used to probe the kinematics of the Galactic disk. Radial velocities are measured for eight distant Cepheids toward l = 300°; these new Cepheids provide a particularly good constraint on the distance to the Galactic center, R0. We model the disk with both an axisymmetric rotation curve and one with a weak elliptical component, and find evidence for an ellipticity of 0.043 ± 0.016 near the Sun. Using these models, we derive R0 = 7.66 ± 0.32 kpc and vcirc = 237 ± 12 km s-1. The distance to the Galactic center agrees well with recent determinations from the distribution of RR Lyrae variables and disfavors most models with large ellipticities at the solar orbit.