Molecular clouds in the Outer Galaxy identified from the MWISP survey

Using the density-based spatial clustering of applications with the noise algorithm, the CO data cubes from the Milky Way Imaging Scroll Painting project were decomposed into a set of discrete molecular clouds. A total of 32,162 molecular clouds are identified, covering the northern Outer Galactic plane (l = [15◦,165◦] and l = [195◦,230◦], and b=[−5.◦25,+5.◦25]). The table includes the basic properties for each molecular cloud. Column 1: cloud number. Columns 2-4: the Galactic coordinates and LSR velocity of the cloud centroid. Column 5: velocity dispersion. Columns 6-8: the Galactic coordinates and LSR velocity of CO emission peak. Column 9: peak main-beam temperature. Column 10: angular area of the cloud. Column 11: total flux of the cloud. Columns 12-13: heliocentric and Galactocentric distance. Columns 14-20: effective radius, excitation temperature, mass, mass surface density, virial parameter, mean H2 number density, internal pressure of the cloud. Column 21: “Y” indicates the cloud is resolved (satisfying the Area≥2.5×2.5 arcmin2 criterion), and “N” indicates the cloud is unresolved. 32,162 12CO molecular clouds that covers the northern Outer Galactic plane8(l = [15◦,165◦] and l = [195◦,230◦], and b=[−5.◦25,+5.◦25]).162 12CO molecular clouds that covers the northern Outer Galactic plane8(l = [15◦,165◦] and l = [195◦,230◦], and b=[−5.◦25,+5.◦25]).

本研究采用基于密度的噪声应用空间聚类算法（Density-Based Spatial Clustering of Applications with Noise，简称DBSCAN），将银河系成像卷轴巡天项目（Milky Way Imaging Scroll Painting project）获取的一氧化碳（CO）数据立方体拆解为一系列离散的分子云。共识别出32162个分子云，覆盖北银道面外盘区域（银经$l in [15^circ, 165^circ]$、$l in [195^circ, 230^circ]$，银纬$b in [-5.25^circ, +5.25^circ]$）。该数据表包含每个分子云的基本属性，各列定义如下：第1列为云团编号；第2至4列为云团质心的银道坐标与局部标准参考系（Local Standard of Rest，LSR）速度；第5列为速度弥散；第6至8列为CO辐射峰值的银道坐标与LSR速度；第9列为峰值主束温度；第10列为云团的角面积；第11列为云团总积分流量；第12至13列为日心距离与银心距离；第14至20列依次为有效半径、激发温度、质量、面质量密度、位力参数、平均氢分子（H₂）数密度以及云团内部压强；第21列为分辨状态标记："Y"表示该云团满足面积≥2.5×2.5平方角分的分辨标准，即已被分辨；"N"表示该云团未被分辨。本数据集包含32162个12CO分子云，覆盖北银道面外盘区域（银经$l in [15^circ, 165^circ]$、$l in [195^circ, 230^circ]$，银纬$b in [-5.25^circ, +5.25^circ]$）。本数据集包含32162个12CO分子云，覆盖北银道面外盘区域（银经$l in [15^circ, 165^circ]$、$l in [195^circ, 230^circ]$，银纬$b in [-5.25^circ, +5.25^circ]$）。