The formation of high-mass binary star systems

Abstract

We develop a semi-analytic model to investigate how accretion onto wide low-mass binary stars can result in a close high-mass binary system. The key ingredient is to allow mass accretion while limiting the gain in angular momentum. We envision this process as being regulated by an external magnetic field during infall. Molecular clouds are made to collapse spherically with material either accreting onto the stars or settling in a disk. Our aim is to determine what initial conditions are needed for the resulting binary to be both massive and close. Whether material accretes, and what happens to the binary separation as a result, depends on the relative size of its specific angular momentum, compared to the specific angular momentum of the binary. When we add a magnetic field we are introducing a torque to the system which is capable of stripping the molecular cloud of some of its angular momentum, and consequently easing the formation of high-mass binaries. Our results suggest that clouds in excess of 1000 M${}_{\odot }$ and radii of 0.5 pc or larger, can easily form binary systems with masses in excess of 25 M${}_{\odot }$ and separations of order 10 R${}_{\odot }$ with magnetic fields of order 100 μG (mass-to-flux ratios of order 5).

9 pages, 5 figures, 1 table, accepted for publication in MNRAS

References in corpus (8)

• Southern Massive Stars at High Angular Resolution: Observational Campaign and Companion Detection
• Circumventing the radiation pressure barrier in the formation of massive stars via disk accretion
• Before the first supernova: combined effects of HII regions and winds on molecular clouds
• Dynamical Simulations of Magnetically Channeled Line-Driven Stellar Winds: III. Angular Momentum Loss and Rotational Spindown
• ATLASGAL --- towards a complete sample of massive star forming clumps
• First hydrodynamics simulations of radiation forces and photoionization feedback in massive star formation
• Protostellar Outflows and Radiative Feedback from Massive Stars
• The Stellar Initial Mass Function and Beyond

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