论文标题
三维气体图的贝叶斯推断：I。银河系
Bayesian inference of three-dimensional gas maps: I. Galactic CO
论文作者
论文摘要
一氧化碳（CO）是银河分子氢（H2）的最佳示踪剂。它的最低旋转发射线位于无线电状态下，由于银河旋转在不同距离处的发射是多普勒的变化。因此，对于给定的气流模型，可以沿视线将观察到的光谱划分以推断气体分布。我们使用Dame等人的CO线调查。 （2001）重建H2的三维密度。我们将删除视为贝叶斯变异推理问题。气体密度的后验分布使我们能够估计重建密度的平均值和不确定性。与以前的大多数尝试不同，我们考虑了各种尺度上气体的相关性，这些量表可以治愈一些众所周知的病理，例如神的手指效应。我们采用的两种气流模型都结合了一个银河棒，该棒诱导了内部几千2杆的径向运动，因此为银河中心提供了光谱分辨率。我们将气体图与早期研究的气体图进行比较，并表征其统计特性，例如平均表面质量密度的径向轮廓。我们已经在https://dx.doi.org/10.5281/zenodo.44405437上为社区提供了三维气体图及其不确定性。
Carbon monoxide (CO) is the best tracer of Galactic molecular hydrogen (H2). Its lowest rotational emission lines are in the radio regime and thanks to Galactic rotation emission at different distances is Doppler shifted. For a given gas flow model the observed spectra can thus be deprojected along the line of sight to infer the gas distribution. We use the CO line survey of Dame et al. (2001) to reconstruct the three-dimensional density of H2. We consider the deprojection as a Bayesian variational inference problem. The posterior distribution of the gas densities allows us to estimate both the mean and uncertainty of the reconstructed density. Unlike most of the previous attempts, we take into account the correlations of gas on a variety of scales which allows curing some of the well-known pathologies, like fingers-of-god effects. Both gas flow models that we adopt incorporate a Galactic bar which induces radial motions in the inner few kiloparsecs and thus offers spectral resolution towards the Galactic centre. We compare our gas maps with those of earlier studies and characterise their statistical properties, e.g. the radial profile of the average surface mass density. We have made our three-dimensional gas maps and their uncertainties available to the community at https://dx.doi.org/10.5281/zenodo.4405437 .
