Details

Autor(en) / Beteiligte

• Yuan, Jinghua
• Li, Jin-Zeng
• Wu, Yuefang
• Ellingsen, Simon P.
• Henkel, Christian
• Wang, Ke
• Liu, Tie
• Liu, Hong-Li
• Zavagno, Annie
• Ren, Zhiyuan
• Huang, Ya-Fang

Titel

High-mass Star Formation through Filamentary Collapse and Clump-fed Accretion in G22

Ist Teil von

• Astrophysical journal. Letters, 2018-01, Vol.852 (1), p.12

Ort / Verlag

Philadelphia: The American Astronomical Society

Erscheinungsjahr

2018

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• How mass is accumulated from cloud-scale down to individual stars is a key open question in understanding high-mass star formation. Here, we present the mass accumulation process in a hub-filament cloud G22 that is composed of four supercritical filaments. Velocity gradients detected along three filaments indicate that they are collapsing with a total mass infall rate of about 440 M Myr−1, suggesting the hub mass would be doubled in six free-fall times, adding up to ∼2 Myr. A fraction of the masses in the central clumps C1 and C2 can be accounted for through large-scale filamentary collapse. Ubiquitous blue profiles in HCO+ (3-2) and 13CO (3-2) spectra suggest a clump-scale collapse scenario in the most massive and densest clump C1. The estimated infall velocity and mass infall rate are 0.31 km s−1 and 7.2 × 10−4 M yr−1, respectively. In clump C1, a hot molecular core (SMA1) is revealed by the Submillimeter Array observations and an outflow-driving high-mass protostar is located at the center of SMA1. The mass of the protostar is estimated to be 11-15 M and it is still growing with an accretion rate of 7 × 10−5 M yr−1. The coexistent infall in filaments, clump C1, and the central hot core in G22 suggests that pre-assembled mass reservoirs (i.e., high-mass starless cores) may not be required to form high-mass stars. In the course of high-mass star formation, the central protostar, the core, and the clump can simultaneously grow in mass via core-fed/disk accretion, clump-fed accretion, and filamentary/cloud collapse.