2015/11/04 by Xiaoliang Zhan, Xiao-Liang Zhan, Zhibo Jiang +4 · 1 citation
Chemistry · Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Atomic and Molecular Physics #Chemistry #Geology #Molecular cloud #Physics #Protein filament #Ridge #Stars #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1088/1674-4527/16/4/056
accepted for publication in RAA; any comment is welcome
arxiv created 2015/11/04 · openalex publication_date 2016/04/01 · arxiv updated 2016/04/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We carried out observations toward the giant molecular cloud W 37 with the J = 1 − 0 transitions of 12 CO, 13 CO and C 18 O using the 13.7m single-dish telescope at the Delingha station of Purple Mountain Observatory. Based on these CO lines, we calculated the column densities and cloud masses for molecular clouds with radial velocities around +20 km s −1 . The gas mass of W 37, calculated from 13 CO emission, is 1.7 × 10 5 M ⊙ , above the criterion to be considered a giant molecular cloud. The dense ridge of W 37 is a dense filament, which is supercritical in terms of linear mass ratio. Dense clumps found by C 18 O emission are aligned along the dense ridge at regular intervals of about 2.8 pc, similar to the clump separation caused by large-scale 'sausage instability'. We confirm the identification of the giant molecular filament (GMF) G 18.0-16.8 and find a new giant filament, G 16.5−15.8, located ∼ 0.7° to the west of G 18.0−16.8. Both GMFs are not gravitationally bound, as indicated by their low linear mass ratio (∼ 80 M ⊙ pc −1 ). We compared the gas temperature map with the dust temperature map from Herschel images, and found similar structures. The spatial distributions of class I objects and the dense clumps are reminiscent of triggered star formation occurring in the northwestern part of W 37, which is close to NGC 6611.