CO–0.30–0.07: A Candidate Site of Collision-induced Massive Star Formation in the Milky Way's Central Molecular Zone

Abstract

Cloud-cloud collision has long been claimed to be an efficient trigger of massive star formation. We present interferometric maps of a candidate site of collision-triggered star formation newly discovered at 40 pc projected distance from the Galactic center. The cloud CO− 0.3 has an extremely broad molecular line emission of a 140 km s −1 velocity width despite of absence of any known energy sources nearby and inside the cloud. Recent observations with the Atacama Large Millimeter and Submillimeter Array have unveiled that the cloud is comprised by two distinctive velocity components which appear to contact at a thin, well-defined interface layer on the plane-of-the-sky, suggesting that the extremely broad emissions originate from shocked regions created by cloud-cloud collision.