太阳圆内的Milky Way自转曲线及其垂直导数
The Milky Way Rotation Curve and its Vertical Derivatives Inside the Solar Circle
摘要：
我们用21厘米VGPS和SGPS测量了银河系第一和第四象限的自转曲线及其前两个垂直导数。我们发现切线速度的原子气体作为银河系的经度和纬度的函数，通过拟合的分析线轮廓的边缘的速度分布。解析剖面的形状仅取决于气体的切向速度和速度弥散。我们使用两种互补的方法来分析切向速度：一个全球模型来拟合典型的参数值和一个本地拟合例程来检查空间变化。我们通过测试简单的模型来确认我们的拟合例程的有效性。整体和局部拟合都与银河系中平面100 pc内旋转曲线的垂直衰减一致，旋转曲线为-22 +/- 6 km/s/kpc。衰减的幅度比仅从电势变化所预期的要大好几倍，这表明其他一些物理过程是重要的。我们测量到的衰减与其他星系晕气体中测量到的衰减大小一致。
英文摘要：
We measure the Galactic rotation curve and its first two vertical derivatives in the first and fourth quadrants of the Milky Way using the 21 cm VGPS and SGPS. We find tangent velocities of the atomic gas as a function of galactic longitude and latitude by fitting an analytic line profile to the edges of the velocity profiles. The shape of the analytic profile depends only on the tangent velocity and the velocity dispersion of the gas. We use two complementary methods to analyze the tangent velocities: a global model to fit typical parameter values and a local fitting routine to examine spatial variations. We confirm the validity of our fitting routines by testing simple models. Both the global and local fits are consistent with a vertical falloff in the rotation curve of -22 +/- 6 km/s/kpc within 100 pc of the Galactic midplane. The magnitude of the falloff is several times larger than what would be expected from the change in the potential alone, indicating some other physical process is important. The falloff we measure is consistent in magnitude with that measured in the halo gas of other galaxies.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
