论文标题
银河系的圆速度曲线从5到25 kpc使用发光的红色巨型分支星星
The Circular Velocity Curve of the Milky Way from 5 to 25 kpc using luminous red giant branch star
论文作者
论文摘要
我们提出了从Apogee和Lamost调查中选择的254,882个发光红色巨型分支（LRGB）星的样品。通过结合来自2MASS和GAIA调查的光度法和天文信息，样品星的精确距离由监督的机器学习算法确定：梯度增强的决策树。为了测试派生距离的准确性，使用了球状簇（GC）和开放簇（OC）的成员恒星。对于我们的样品恒星的衍生距离，群集成员恒星的测试显示出约10％的精度。最终样本涵盖了大量的银河磁盘和$ 0 <r <r <30 $ kpc和$ | z | \ leqslant15 $ kpc的光环。银河系的旋转曲线（RC）在半径上的$ 5 \ Lessim r \ Lessim25 $ kpc已通过$ \ sim $ \ sim $ 54,000恒星的精确测量，其中从LRGB样品中选择了薄磁盘总体。 The derived RC shows a weak decline along $R$ with a gradient of $-1.83\pm0.02$ $({\rm stat.}) \pm 0.07$ $({\rm sys.})$ km s$^{-1}$ kpc$^{-1}$, in excellent agreement with the results measured by previous studies.由我们的RC产生的太阳位置的圆速度为$ 234.04 \ pm0.08 $ $（{\ rm Stat。}）\ pm 1.36 $ $（{\ rmsys。Sys。}）$ s $ s $ s $ s $ s $^{ - 1} $，再次与其他独立的独立确定非常一致。从新建的RC以及其他数据的约束中，我们已经为银河系构建了一个质量模型，产生了$ m _ {\ rm {200}} $ =（$ 8.05 \ pm1.15 $ \ pm1.15 $ \ times $ 10 $^times $ 10 $^{11} {11} \ rm___________________________________________________________ $ r _ {\ rm {200}} $ = $ 192.37 \ pm9.24 $ kpc和本地暗物质密度$ 0.39 \ pm0.03 $ gev cm $^{ - 3} $。
We present a sample of 254,882 luminous red giant branch (LRGB) stars selected from the APOGEE and LAMOST surveys. By combining photometric and astrometric information from the 2MASS and Gaia surveys, the precise distances of the sample stars are determined by a supervised machine learning algorithm: the gradient boosted decision trees. To test the accuracy of the derived distances, member stars of globular clusters (GCs) and open clusters (OCs) are used. The tests by cluster member stars show a precision of about 10 per cent with negligible zero-point offsets, for the derived distances of our sample stars. The final sample covers a large volume of the Galactic disk(s) and halo of $0<R<30$ kpc and $|Z|\leqslant15$ kpc. The rotation curve (RC) of the Milky Way across radius of $5\lesssim R\lesssim25$ kpc have been accurately measured with $\sim$ 54,000 stars of the thin disk population selected from the LRGB sample. The derived RC shows a weak decline along $R$ with a gradient of $-1.83\pm0.02$ $({\rm stat.}) \pm 0.07$ $({\rm sys.})$ km s$^{-1}$ kpc$^{-1}$, in excellent agreement with the results measured by previous studies. The circular velocity at the solar position, yielded by our RC, is $234.04\pm0.08$ $({\rm stat.}) \pm 1.36$ $({\rm sys.})$ km s$^{-1}$, again in great consistent with other independent determinations. From the newly constructed RC, as well as constraints from other data, we have constructed a mass model for our Galaxy, yielding a mass of the dark matter halo of $M_{\rm{200}}$ = ($8.05\pm1.15$)$\times$10$^{11} \rm{M_\odot}$ with a corresponding radius of $R_{\rm{200}}$ = $192.37\pm9.24$ kpc and a local dark matter density of $0.39\pm0.03$ GeV cm$^{-3}$.
