Large-scale CO (J = 1–0) Observations toward the M120.1+3.0 Molecular Cloud: A Filament with a Chain of Starburst Clusters

Abstract

Abstract We present large-scale (2° × 2°) observations toward the molecular cloud M120.1+3.0, using 12CO, 13CO and C18O (J = 1 − 0) data from the Purple Mountain Observatory 13.7 m millimeter telescope. The distance of the cloud is measured to be ∼1.1 kpc. Using the 13CO data, we identify a main filament F1 and two sub-filaments F2 and F3 in the cloud, which together show a “hub-filament” structure. Filaments F1 and F2 are thermally supercritical. Furthermore, F1 displays clear localized systematic motions in the 13CO position–velocity diagram, which could be explained by accretion along the filament. The mean estimated accretion rate is ∼132 M ⊙ Myr−1. Approximately 150 13CO clumps are identified in the cloud, of which 39 are gravitationally bound. Most of these virialized clumps are well distributed along the supercritical filaments F1 and F2. Based on the complementary infrared and optical data, we identify ∼186 young stellar objects in the observed area and extract five clusters within the dense ridge of F1. The calculated star formation rate (SFR) surface densities (ΣSFR) in the clusters range from 1.4 to 2.5 M ⊙ Myr−1 pc−2, with a mean value of ∼2.0 M ⊙ Myr−1 pc−2. We therefore regard them as mini-starburst cluster candidates. The comparison between ΣSFR and column density N gas along the skeleton of F1 suggests that star formation is closely related to the dense gas in the cloud. Along the main filament F1, five bipolar outflows are also found. All these results indicate intense star-forming activities in the M120.1+3.0 molecular cloud.