We present a three-dimensional (3D) extinction map of the southern sky. The map covers the SkyMapper Southern Survey (SMSS) area of $\sim$ 14,000 ${\rm deg^{2}}$ and has spatial resolutions between 6.9 and 27 arcmin. Based on the multi-band photometry of SMSS, the Two Micron All Sky Survey, the Wide-Field Infrared Survey Explorer Survey and the Gaia mission, we have estimated values of the $r$-band extinction for $\sim$ 19 million stars with the spectral energy distribution (SED) analysis. Together with the distances calculated from the Gaia data release 2 (DR2) parallaxes, we have constructed a three-dimensional extinction map of the southern sky. By combining our 3D extinction map with those from the literature, we present an all-sky 3D extinction map, and use it to explore the 3D distribution of the Galactic dust grains. We use two different models, one consisting a single disk and another of two disks, to fit the 3D distribution of the Galactic dust grains. The data is better fitted by a two-disk model, yielding smaller values of the Bayesian Information Criterion (BIC). The best fit model has scale heights of 73 and 225 pc for the "thin" and "thick" dust disks, respectively.

中文翻译：

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银河系星际尘埃的三维分布

我们展示了南方天空的三维 (3D) 灭绝图。该地图涵盖了价值 $\sim$ 14,000 ${\rm deg^{2}}$ 的 SkyMapper Southern Survey (SMSS) 区域，空间分辨率介于 6.9 和 27 弧分之间。基于 SMSS 的多波段测光、两微米全天巡天、广域红外巡天探索者巡天和盖亚任务，我们估算了 $\sim$ 1900 万颗恒星的 $r$-波段消光值光谱能量分布 (SED) 分析。结合根据盖亚数据第 2 版（DR2）视差计算的距离，我们构建了南方天空的三维消光图。通过将我们的 3D 灭绝图与文献中的那些相结合，我们提出了一个全天空 3D 灭绝图，并用它来探索银河尘埃颗粒的 3D 分布。我们使用两种不同的模型，一种由单个圆盘组成，另一个由两个圆盘组成，以拟合银河尘埃颗粒的 3D 分布。数据更好地由两盘模型拟合，产生更小的贝叶斯信息准则 (BIC) 值。对于“薄”和“厚”尘盘，最佳拟合模型的比例高度分别为 73 和 225 pc。