Dependence of Molecular Cloud Samples on Angular Resolution, Sensitivity, and Algorithms

In this work, we investigate the observational and algorithmic effects on molecular cloud samples identified from position-position-velocity (PPV) space. By smoothing cutting off high quality data of Milky Way Imaging Scroll Painting (MWISP) survey, extract various those altered with DBSCAN (density-based spatial clustering applications noise) algorithm. Those are subsequently used to gauge significance sensitivity, angular/velocity resolution, parameters. Two additional surveys, FCRAO Outer Galaxy Survey (OGS) CfA-Chile 1.2 m complete CO (CfA-Chile) verify MWISP results. We found that catalogs not unique boundary therefore number shows strong variation angular resolution sensitivity. At low (large beam sizes), clouds merge together in PPV space, while sensitivity (high cutoffs) misses small faint takes bright parts large as single ones. giant (GMCs) resolved into individual clouds, their diffuse components also revealed. Consequently, GMCs more appropriately interpreted clusters or aggregates i.e., represent themselves.