The inception of star cluster formation revealed by [C II] emission around an Infrared Dark Cloud

July 2018 • 2018MNRAS.478L..54B

Authors • Bisbas, Thomas G. • Tan, Jonathan C. • Csengeri, Timea • Wu, Benjamin • Lim, Wanggi • Caselli, Paola • Güsten, Rolf • Ricken, Oliver • Riquelme, Denise

Abstract • We present SOFIA-upGREAT observations of [C II] emission of Infrared Dark Cloud (IRDC) G035.39-00.33, designed to trace its atomic gas envelope and thus test models of the origins of such clouds. Several velocity components of [C II] emission are detected, tracing structures that are at a wide range of distances in the Galactic plane. We find a main component that is likely associated with the IRDC and its immediate surroundings. This strongest emission component has a velocity similar to that of the ¹³CO(2-1) emission of the IRDC, but offset by ∼3 km s^-1 and with a larger velocity width of ∼9 km s^-1. The spatial distribution of the [C II] emission of this component is also offset predominantly to one side of the dense filamentary structure of the IRDC. The C II column density is estimated to be of the order of ∼10¹⁷-10¹⁸ cm^-2. We compare these results to the [C II] emission from numerical simulations of magnetized, dense gas filaments formed from giant molecular cloud (GMC) collisions, finding similar spatial and kinematic offsets. These observations and modellingof [C II] add further to the evidence that IRDC G035.39-00.33 has been formed by a process of GMC-GMC collision, which may thus be an important mechanism for initiating star cluster formation.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2018MNRAS.478L..54B
• PDF http://academic.oup.com/mnrasl/pdf-lookup/doi/10.1093/mnrasl/sly039
• PREPRINT http://arxiv.org/abs/1803.00566
• DATA https://irsa.ipac.caltech.edu/bibdata/2018/B/2018MNRAS.478L..54B.html
• ELECTR https://doi.org/10.1093%2Fmnrasl%2Fsly039