Searching for further evidence for cloud–cloud collisions in L1188

Abstract

In order to search for further observational evidence of cloud-cloud collisions in one of the promising candidates, L1188, we carried out observations of multiple molecular lines toward the intersection region of the two nearly orthogonal filamentary molecular clouds in L1188. Based on these observations, we find two parallel filamentary structures, both of which have at least two velocity components being connected with broad bridging features. We also found a spatially complementary distribution between the two molecular clouds, as well as enhanced 13 CO emission and 12 CO self-absorption toward their abutting regions. At the most blueshifted velocities, we unveil a 1 pc-long arc ubiquitously showing 12 CO line wings. We discover two 22 GHz water masers, which are the first maser detections in L1188. An analysis of line ratios at a linear resolution of 0.2 pc suggests that L1188 is characterised by kinetic temperatures of 13-23 K and H 2 number densities of 10 3 -10 3.6 cm −3 . On the basis of previous theoretical predictions and simulations, we suggest that these observational features can be naturally explained by the scenario of a cloud-cloud collision in L1188, although an additional contribution of stellar feedback from low-mass young stellar objects cannot be ruled out.

Cloud–Cloud Collision and Cluster Formation in the W5-NW Complex

“…Recent observational studies provide ample evidence supporting the key role played by CCC in star formation. Studies have shown induced high-mass star and cluster formation (e.g., Issac et al 2020a;Fukui et al 2021), formation of super star clusters (e.g., Fukui et al 2014Fukui et al , 2016, low-and intermediate-mass stars (e.g., Gong et al 2017Gong et al , 2019 and massive star clusters (e.g., Sano et al 2018;Issac et al 2020a). CCC resulting in the formation of single O-type stars with surrounding H II regions has also been observed (e.g., Torii et al 2015Torii et al , 2017.…”