Impact of Magnetic Braking on High-mass Close Binary Formation

Abstract

Combining numerical simulations and analytical modeling, we investigate whether close binary systems form by the effect of magnetic braking. Using magnetohydrodynamics simulations, we calculate the cloud evolution with a sink, for which we do not resolve the binary system or binary orbital motion to realize long-term time integration. Then, we analytically estimate the binary separation using the accreted mass and angular momentum obtained from the simulation. In unmagnetized clouds, wide binary systems with separations of >100 au form, in which the binary separation continues to increase during the main accretion phase. In contrast, close binary systems with separations of <100 au can form in magnetized clouds. Since the efficiency of magnetic braking strongly depends on both the strength and configuration of the magnetic field, they also affect the formation conditions of a close binary. In addition, the protostellar outflow has a negative impact on close binary formation, especially when the rotation axis of the prestellar cloud is aligned with the global magnetic field. The outflow interrupts the accretion of gas with small angular momentum, which is expelled from the cloud, while gas with large angular momentum preferentially falls from the side of the outflow onto the binary system and widens the binary separation. This study shows that a cloud with a magnetic field that is not parallel to the rotation axis is a favorable environment for the formation of close binary systems.

arXiv commentAccepted for publication in MNRAS

References in corpus (43)

• The Formation of the First Star in the Universe
• Stellar Multiplicity
• Mind your Ps and Qs: the Interrelation between Period (P) and Mass-ratio (Q) Distributions of Binary Stars
• Open data from the first and second observing runs of Advanced LIGO and Advanced Virgo
• Stellar, brown dwarf and multiple star properties from a radiation hydrodynamical simulation of star cluster formation
• Stellar, Brown Dwarf, and Multiple Star Properties from Hydrodynamical Simulations of Star Cluster Formation
• Evolution of Massive Protostars with High Accretion Rates
• The Formation of Close Binary Systems by Dynamical Interactions and Orbital Decay
• Protostellar disk formation and transport of angular momentum during magnetized core collapse
• Evolution of Massive Protostars via Disk Accretion
• Disk formation during collapse of magnetized protostellar cores
• Magnetic processes in a collapsing dense core. II Fragmentation. Is there a fragmentation crisis ?
• The formation of close binary systems
• Effect of Magnetic Braking on the Circumstellar Disk Formation in a Strongly Magnetized Cloud
• Magnetic Fields and Rotations of Protostars
• Binary systems and stellar mergers in massive star formation
• Fragmentation of a Molecular Cloud Core versus Fragmentation of the Massive Protoplanetary Disk in the Main Accretion Phase
• Evolution of Protostellar Outflow around Low-mass Protostar
• Collapse and Fragmentation of Rotating Magnetized Clouds. I. Magnetic Flux - Spin Relation
• Formation Scenario for Wide and Close Binary Systems
• The influence of turbulence during magnetized core collapse and its consequences on low-mass star formation
• Self-similar Fragmentation Regulated by Magnetic Fields in a Massive Star Forming Filament
• Turbulence-induced disc formation in strongly magnetised cloud cores
• First MHD Simulation of Collapse and Fragmentation of Magnetized Molecular Cloud Cores
• The dependence of star formation on initial conditions and molecular cloud structure
• Forming spectroscopic massive proto-binaries by disk fragmentation
• Formation and Evolution of Disks around Young Stellar Objects
• Impact of Protostellar Outflow on Star Formation: Effects of Initial Cloud Mass
• Massive Outflows Driven by Magnetic Effects in Star Forming Clouds with High Mass Accretion Rates
• The Effect of Misalignment between Rotation Axis and Magnetic Field on Circumstellar Disk
• The Circumbinary Outflow: A Protostellar Outflow Driven by a Circumbinary Disk
• Misalignment of Magnetic Fields, Outflows and Discs in Star-forming Clouds
• Does misalignment between magnetic field and angular momentum enhance or suppress circumstellar disk formation?
• Smoothed particle magnetohydrodynamic simulations of protostellar outflows with misaligned magnetic field and rotation axes
• Binary Star Formation and the Outflows from their Discs
• Massive Outflows Driven by Magnetic Effects II: Comparison with Observations
• The dependence of protostar formation on the geometry and strength of the initial magnetic field
• Failed and delayed protostellar outflows with high mass accretion rates
• Misaligned Twin Molecular Outflows From Class-0 Proto-stellar Binary System VLA 1623A Unveiled by ALMA
• Different Modes of Star Formation II: Gas Accretion Phase of Initially Subcritical Star-Forming Clouds
• The formation of high-mass binary star systems
• Twin Jets and Close Binary Formation
• Evolution of binary seeds in collapsing protostellar gas clouds

Cited by in corpus (7)

• Gaia Spectroscopic Orbits Validated with LAMOST and GALAH Radial Velocities
• The role of magnetic fields in the formation of multiple massive stars
• Discovery of a 500 au Protobinary in the Massive Prestellar Core G11.92-0.61 MM2
• Merger Conditions of Population III Protostar Binaries
• Wide-binary eccentricity distribution in young star clusters: dependence on the binary separation and mass
• Fragmentation of Dense Rotation-Dominated Structures Fed by Collapsing Gravomagneto-Sheetlets and Origin of Misaligned 100 au-Scale Binaries and Multiple Systems
• Evolutionary models for the Very Massive Stars in the R136 cluster of 30 Doradus in the Large Magellanic Cloud