| Title | A Morphological Classification of 18,190 Molecular Clouds Identified in (CO)-C-12 Data from the MWISP Survey |
| Authors | Yuan, Lixia Yang, Ji Du, Fujun Liu, Xunchuan Zhang, Shaobo Lin, Zehao Sun, Jingfei Yan, Qing-Zeng Ma, Yuehui Su, Yang Sun, Yan Zhou, Xin |
| Affiliation | Chinese Acad Sci, Purple Mt Observ, 10 Yuanhua Rd, Nanjing 210033, Peoples R China Chinese Acad Sci, Key Lab Radio Astron, 10 Yuanhua Rd, Nanjing 210033, Peoples R China Peking Univ, Dept Astron, 5 Yiheyuan Rd, Beijing 100871, Peoples R China |
| Keywords | SMALL DARK CLOUDS H-II REGION STAR-FORMATION FILAMENTS FRAGMENTATION CO OUTFLOWS EVOLUTION EMISSION GLOBULES |
| Issue Date | Dec-2021 |
| Publisher | ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES |
| Abstract | We attempt to visually classify the morphologies of 18,190 molecular clouds, which are identified in the (CO)-C-12(1-0) spectral line data over similar to 450 deg(2) of the second Galactic quadrant from the Milky Way Imaging Scroll Painting project. Using the velocity-integrated intensity maps of the (CO)-C-12(1-0) emission, molecular clouds are first divided into unresolved and resolved ones. The resolved clouds are further classified as nonfilaments or filaments. Among the 18,190 molecular clouds, similar to 25% are unresolved, similar to 64% are nonfilaments, and similar to 11% are filaments. In the terms of the integrated flux of (CO)-C-12(1-0) spectra of all 18,190 molecular clouds, similar to 90% are from filaments, similar to 9% are from nonfilaments, and the remaining similar to 1% are from unresolved sources. Although nonfilaments are dominant in the number of the discrete molecular clouds, filaments are the main contributor of (CO)-C-12 emission flux. We also present the number distributions of the physical parameters of the molecular clouds in our catalog, including their angular sizes, velocity spans, peak intensities of (CO)-C-12(1-0) emission, and (CO)-C-12(1-0) total fluxes. We find that there is a systematic difference between the angular sizes of the nonfilaments and filaments, with the filaments tending to have larger angular scales. The H-2 column densities of them are not significantly different. We also discuss the observational effects, such as those induced by the finite spatial resolution, beam dilution, and line-of-sight projection, on the morphological classification of molecular clouds in our sample. |
| URI | http://hdl.handle.net/20.500.11897/631332 |
| ISSN | 0067-0049 |
| DOI | 10.3847/1538-4365/ac242a |
| Indexed | SCI(E) |
| Appears in Collections: | 物理学院 |
