DISCOVERY OF INFALLING MOTION WITH ROTATION OF THE CLUSTER-FORMING CLUMP S235AB AND ITS IMPLICATION TO THE CLUMP STRUCTURES

作者：Shimoikura Tomomi^*; Dobashi Kazuhito; Matsumoto Tomoaki; Nakamura Fumitaka

来源：Astrophysical Journal, 2016, 832(2): 205.

DOI：10.3847/0004-637X/832/2/205

• ISM: clouds
• ISM: individual (S235)
• ISM: kinematics and dynamics
• ISM: molecules
• stars: formation

We report the discovery of infalling motion with the rotation of S235AB, a massive cluster-forming clump (similar to 1 x 10(3) M-circle dot) in the S235 region. Our (CO)-O-18 observations with the 45 m telescope at the Nobeyama Radio Observatory have revealed an elliptical shape of the clump. A position-velocity diagram taken along its major axis exhibits two well-defined peaks symmetrically located, with respect to the clump center. This is similar to that found for a dynamically infalling envelope with rotation around a single protostar, modeled by N. Ohashi et al., indicating that the cluster-forming clump is also collapsing by the self-gravity toward the clump center. With analogue to Ohashi et al.'s model, we made a simple model of an infalling, rotating clump to fit the observed data. Based on the inferred model parameters, as well as results of earlier observations and simulations in the literature, we discuss the structures of the clump such as the relation among the global mass infall rate (similar to 1 x 10(3) M-circle dot yr(-1)), formation of a compact core (with a mass and size of similar to 4 M. and less than or similar to 0.1 pc) at the center, and a massive star (similar to 11 M-circle dot) forming in the core.

• 出版日期2016-12-1
• 单位中国科学院国家天文台