论文标题
高银河纬度沿着视线的HI云数的地图
Maps of the number of HI clouds along the line of sight at high galactic latitude
论文作者
论文摘要
在三个维度上表征银河系介质（ISM）的结构对于将灰尘发射作为宇宙微波背景（CMB）的前景进行精确建模而言至关重要。在高银河纬度上，缺少ISM的3D结构的总灰尘含量很低，精确的地图。我们开发了一种使用HI线发射的方法来量化沿视线的灰尘分布的复杂性。该方法依赖于HI光谱的高斯分解，以使发射的速度重叠成分。我们使用此信息来创建视线沿线云数的地图。我们将方法应用于：（a）高半乳酸纬度天空和（b）二头肌/凯克实验靶向的区域。在北银河上限，我们平均每0.2平方英尺像素，而在南部，数量下降到2.5。云数的统计数据受中速云（IVC）的影响，主要位于北部。 IVC的存在导致\ textit {planck}测得的灰尘发射中可检测到的特征。我们研究了二头肌/凯克地区HI光谱的复杂性，并找到了沿视线存在多个组件的证据。数据（https://doi.org/10.7910/dvn/8da5lh）和软件已公开可用，可用于通知CMB前景建模和3D防尘映射。
Characterizing the structure of the Galactic interstellar medium (ISM) in three dimensions is of high importance for accurate modeling of dust emission as a foreground to the Cosmic Microwave Background (CMB). At high Galactic latitude, where the total dust content is low, accurate maps of the 3D structure of the ISM are lacking. We develop a method to quantify the complexity of the distribution of dust along the line of sight with the use of HI line emission. The method relies on a Gaussian decomposition of the HI spectra to disentangle the emission from overlapping components in velocity. We use this information to create maps of the number of clouds along the line of sight. We apply the method to: (a) the high-galactic latitude sky and (b) the region targeted by the BICEP/Keck experiment. In the North Galactic Cap we find on average three clouds per 0.2 square degree pixel while in the South the number falls to 2.5. The statistics of the number of clouds are affected by Intermediate-Velocity Clouds (IVCs), primarily in the North. The presence of IVCs results in detectable features in the dust emission measured by \textit{Planck}. We investigate the complexity of HI spectra in the BICEP/Keck region and find evidence for the existence of multiple components along the line of sight. The data (https://doi.org/10.7910/DVN/8DA5LH) and software are made publicly available, and can be used to inform CMB foreground modeling and 3D dust mapping.
