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arXiv 2302.01618astro-ph.GA
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根据 Gaia EDR3 目录研究经典造父变星的三维运动学

3-D kinematics of classical Cepheids according to Gaia, EDR3 catalog

V. V. Bobylev, A. T. Bajkova

AI总结:

基于 Gaia EDR3 数据,本文研究了约 2000 颗银河系经典造父变星的三维运动学,利用非线性旋转模型测定了银河系旋转曲线参数,并发现垂直速度梯度 $\partial W/\partial x$ 显著,揭示了银河系盘面恒星垂直速度受扰动的间接效应。

摘要:

本文利用 Gaia EDR3 目录的数据,研究了银河系中约 2000 颗经典造父变星的运动学。对于其中部分恒星,存在视线方向速度。基于非线性旋转模型,确定了银河系旋转曲线的参数。在假设太阳到银河系中心的距离为 $R_0=8.1\pm0.1$~kpc 的情况下,太阳附近邻域绕银河系中心的圆周线性旋转速度为 $V_0=236\pm 3$~km s$^{-1}$。基于线性 Ogorodnikov-Milne 模型对造父变星剩余速度的分析表明,存在以下显著不为零的梯度:$\partial U/\partial x$、$\partial U/\partial z$、$\partial V/\partial x$、$\partial V/\partial z$ 和 $\partial W/\partial x$,这些梯度根据选取半径的不同表现出不同的行为。最有趣的是梯度 $\partial W/\partial x\sim-0.5\pm0.1$~km s$^{-1}$ kpc$^{-1}$(该恒星系统绕银河系轴 $y$ 的正向旋转,$Ω_y$),因为速度 $W$ 不受银河系旋转的影响。在此,我们观察到各种效应的间接影响,这些效应导致银河系盘面恒星垂直速度受到扰动。基于一个更简单的模型,获得了该旋转的更精确估计值,$Ω_y=0.51\pm0.07$~km s$^{-1}$ kpc$^{-1}$。

英文摘要:

The kinematics of about 2000 classical Cepheids of the Milky Way with data from Gaia\,EDR3 catalog has been studied. For some of these stars, there are line-of-sight velocities. On the basis of the nonlinear rotation model, the parameters of the rotation curve of the Galaxy were determined. The circular linear rotation velocity of the near-solar neighborhood around the Galaxy center was $V_0=236\pm 3$~km s$^{-1}$ for the assumed Sun's galactocentric distance $R_0=8.1\pm0.1$~kpc. Analysis of residual velocities of Cepheids based on the linear Ogorodnikov-Milne model showed the presence of the following significantly different from zero gradients: $\partial U/\partial x,$ $\partial U/\partial z,$ $\partial V/\partial x,$ $\partial V/\partial z$ and $\partial W/\partial x,$ which behaves differently depending on the selection radius. The most interesting is the gradient $\partial W/\partial x\sim-0.5\pm0.1$~km s$^{-1}$ kpc$^{-1}$ (positive rotation of this star system around the galactic axis $y$, $Ω_y$) since the velocities $W$ are free of galactic rotation. Here we have an indirect influence of various effects leading to a perturbation of the vertical velocities of the galactic disk stars. Based on a simpler model, a more accurate estimate of this rotation is obtained, $Ω_y=0.51\pm0.07$~km s$^{-1}$ kpc$^{-1}$.

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。

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