Fragmentation of the High-mass “Starless” Core G10.21-0.31: A Coherent Evolutionary Picture for Star Formation

Abstract

G10.21-0.31 is a 70 μ m dark high-mass starless core ( M > 300 M _⊙ within r < 0.15 pc) identified in the Spitzer, Herschel, and APEX continuum surveys, and is believed to harbor the initial stages of high-mass star formation. We present Atacama Large Millimeter/submillimeter Array (ALMA) and Submillimeter Array observations to resolve the internal structure of this promising high-mass starless core. Sensitive high-resolution ALMA 1.3 mm dust continuum emission reveals three cores of mass ranging within 11–18 M _⊙ , characterized by a turbulent fragmentation. Cores 1, 2, and 3 represent a coherent evolution of three different stages, characterized by outflows (CO and SiO), gas temperature (H _2 CO), and deuteration (N _2 D ^+ /N _2 H ^+ ). We confirm the potential for formation of high-mass stars in G10.21 and explore the evolution path of high-mass star formation. Yet, no high-mass prestellar core is present in G10.21. This suggests a dynamical star formation where cores grow in mass over time.

Keywords

• Massive stars
• Infrared dark clouds
• Star formation
• Protostars