论文标题
使用恒星流的Gaia EDR3观测值测量太阳的速度
Measuring the Sun's velocity using Gaia EDR3 observations of Stellar Streams
论文作者
论文摘要
我们使用Gaia的早期数据版本3（EDR3）观测值测量了太阳相对于银河光环的速度。我们的方法依赖于以下事实：在低质量流中，应在银河系的非旋转休息框架中沿着溪流结构进行正确的运动，但是由于太阳自身的反射运动而产生了观察到的偏差。该原理使我们能够实施一个简单的几何过程，我们用它来分析$ \ sim 3-30 $ kpc范围内的17个流。我们对太阳运动的限制与任何银河电位模型无关，并且它与太阳的半乳酸距离也不相关。我们将太阳的速度推断为$ v_ {r，\ odot} = 8.88^{+1.20} _ { - 1.22} \，\ rm {kms^{ - 1}} $（径向朝向银河中心）， $ v_ {ϕ，\ odot} = 241.91^{+1.61} _ { - 1.73} \，\ rm {kms^{ - 1}} $ $ v_ {z，\ odot} = 3.08^{+1.06} _ { - 1.10} \，\ rm {kms^{ - 1}} $（垂直向上）与过去测量其他技术的全球一致；尽管我们确实注意到$ v_ {z，\ odot} $组件的很小但显着差异。其中一些参数显示出显着的相关性，我们提供了MCMC输出，因此读者可以将其用作未来工作的输入。使用其他参考框架，我们的太阳速度推断与先前结果之间的比较表明，内部银河系并未相对于由晕圈流定义的惯性框架移动。
We measure the Sun's velocity with respect to the Galactic halo using Gaia Early Data Release 3 (EDR3) observations of stellar streams. Our method relies on the fact that, in low-mass streams, the proper motion of stars should be directed along the stream structure in a non-rotating rest frame of the Galaxy, but the observed deviation arises due to the Sun's own reflex motion. This principle allows us to implement a simple geometrical procedure, which we use to analyse 17 streams over a $\sim 3-30$ kpc range. Our constraint on the Sun's motion is independent of any Galactic potential model, and it is also uncorrelated with the Sun's galactocentric distance. We infer the Sun's velocity as $V_{R,\odot}=8.88^{+1.20}_{-1.22}\,\rm{kms^{-1}}$ (radially towards the Galactic centre), $V_{ϕ,\odot}=241.91^{+1.61}_{-1.73}\,\rm{kms^{-1}}$ (in the direction of Galactic rotation) and $V_{z,\odot}=3.08^{+1.06}_{-1.10}\,\rm{kms^{-1}}$ (vertically upwards), in global agreement with past measurements through other techniques; although we do note a small but significant difference in the $V_{z,\odot}$ component. Some of these parameters show significant correlation and we provide our MCMC output so it can be used by the reader as an input to future works. The comparison between our Sun's velocity inference and previous results, using other reference frames, indicates that the inner Galaxy is not moving with respect to the inertial frame defined by the halo streams.
