论文标题
盖亚时代的卫星适当动作的我们的银河系质量
The mass of our Galaxy from satellite proper motions in the Gaia era
论文作者
论文摘要
我们使用Watkins等人的尺度游离质量估计器，使用45个卫星星系的GAIA DR2全身运动来限制银河系的质量。 （2010）。我们首先确定各向异性参数$β$，示踪剂卫星的径向密度指数$γ$为$β$ = $ -0.67^{+0.45} _ { - 0.62} $和$γ= 2.11 \ pm0.23 $。当我们排除大麦芽云的可能以前的卫星时，各向异性变为$β$ = $ -0.21^{+0.37} _ { - 0.51} $。我们发现，取决于质量本身的银河系重力潜力$α$的指数是对质量测定的影响最大的参数。通过与银河系样星系的宇宙学模拟进行比较，我们对观察性不确定性的估计及其对质量估计量的影响进行了详细的分析。我们发现，当天真地应用于模拟的银河系光环卫星时，质量估计器会偏置。纠正这种偏见，我们为我们的星系获得了$ 0.58^{+0.15} _ { - 0.14} \ times10^{12} $ M $ _ \ odot $在64 kpc之内，如我们观察者样本的内部和64 kpc之内$ 1.43^{+0.35} _ { - 0.32} \ times10^{12} $ m $ _ \ odot $在273 kpc之内，来自完整示例；后一个值外推到病毒质量为$ m_ \ mathrm {vir \，δ= 97} $ = $ 1.51^{+0.45} _ { - 0.40} \ 0.40} \ times 10^{12} {12} m _ {\ odot} KPC。银河系的这种值质量在文献中从各种不同方法中报道的其他质量估计之间。
We use Gaia DR2 systemic proper motions of 45 satellite galaxies to constrain the mass of the Milky Way using the scale free mass estimator of Watkins et al. (2010). We first determine the anisotropy parameter $β$, and the tracer satellites' radial density index $γ$ to be $β$=$-0.67^{+0.45}_{-0.62}$ and $γ=2.11\pm0.23$. When we exclude possible former satellites of the Large Magellanic Cloud, the anisotropy changes to $β$=$-0.21^{+0.37}_{-0.51}$. We find that the index of the Milky Way's gravitational potential $α$, which is dependent on the mass itself, is the parameter with the largest impact on the mass determination. Via comparison with cosmological simulations of Milky Way-like galaxies, we carried out a detailed analysis of the estimation of the observational uncertainties and their impact on the mass estimator. We found that the mass estimator is biased when applied naively to the satellites of simulated Milky Way halos. Correcting for this bias, we obtain for our Galaxy a mass of $0.58^{+0.15}_{-0.14}\times10^{12}$M$_\odot$ within 64 kpc, as computed from the inner half of our observational sample, and $1.43^{+0.35}_{-0.32}\times10^{12}$M$_\odot$ within 273 kpc, from the full sample; this latter value extrapolates to a virial mass of $M_\mathrm{vir\,Δ=97}$=$1.51^{+0.45}_{-0.40} \times 10^{12}M_{\odot}$ corresponding to a virial radius of R$_\mathrm{vir}$=$308\pm29$ kpc. This value of the Milky Way mass lies in-between other mass estimates reported in the literature, from various different methods.
