Formation Scenario for Wide and Close Binary Systems

Abstract

Fragmentation and binary formation processes are studied using three-dimensional resistive MHD nested grid simulations. Starting with a Bonnor-Ebert isothermal cloud rotating in a uniform magnetic field, we calculate the cloud evolution from the molecular cloud core (n=10^4 cm^-3) to the stellar core (n \simeq 10^22 cm^-3). We calculated 147 models with different initial magnetic, rotational, and thermal energies, and the amplitudes of the non-axisymmetric perturbation. In a collapsing cloud, fragmentation is mainly controlled by the initial ratio of the rotational to the magnetic energy, regardless of the initial thermal energy and amplitude of the non-axisymmetric perturbation. When the clouds have large rotational energies in relation to magnetic energies, fragmentation occurs in the low-density evolution phase (10^12 cm^-3 < n < 10^15 cm^-3) with separations of 3-300 AU. Fragments that appeared in this phase are expected to evolve into wide binary systems. On the other hand, fragmentation does not occur in the low-density evolution phase, when initial clouds have large magnetic energies in relation to the rotational energies. In these clouds, fragmentation only occurs in the high-density evolution phase (n > 10^17 cm^-3) after the clouds experience significant reduction of the magnetic field owing to Ohmic dissipation in the period of 10^12 cm^-3 < n < 10^15 cm^-3. Fragments appearing in this phase have separations of < 0.3 AU, and are expected to evolve into close binary systems. As a result, we found two typical fragmentation epochs, which cause different stellar separations. Although these typical separations are disturbed in the subsequent gas accretion phase, we might be able to observe two peaks of binary separations in extremely young stellar groups.

45 pages,12 figures, Submitted to ApJ, For high resolution figures see http://www2.scphys.kyoto-u.ac.jp/~machidam/protostar/proto/main-astroph.pdf

References in corpus (37)

• The Formation of a Star Cluster: Predicting the Properties of Stars and Brown Dwarfs
• Dense Cores in Dark Clouds. XIV. N2H+(1-0) maps of dense cloud cores
• Thermal and Fragmentation Properties of Star-forming Clouds in Low-metallicity Environments
• A High Order Godunov Scheme with Constrained Transport and Adaptive Mesh Refinement for Astrophysical MHD
• Unveiling the Circumstellar Envelope and Disk: A Sub-Arcsecond Survey of Circumstellar Structures
• The Formation Mechanism of Brown Dwarfs
• Stellar Multiplicity and the IMF: Most Stars Are Single
• Magnetic processes in a collapsing dense core. I Accretion and Ejection
• The impact of magnetic fields on single and binary star formation
• Outflows and Jets from Collapsing Magnetized Cloud Cores
• Collapse of a Molecular Cloud Core to Stellar Densities: The First Three-Dimensional Calculations
• Simulating star formation in molecular cloud cores I. The influence of low levels of turbulence on fragmentation and multiplicity
• Mechanism of Magnetic Flux Loss in Molecular Clouds
• Collapse of Rotating Magnetized Molecular Cloud Cores and Mass Outflows
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• Magnetic processes in a collapsing dense core. II Fragmentation. Is there a fragmentation crisis ?
• Magnetic Fields and Rotations of Protostars
• Near Infrared Imaging Survey of Bok Globules: Density Structure
• Collapse-Driven Outflow in Star-Forming Molecular Cores
• Fragmentation of a Molecular Cloud Core versus Fragmentation of the Massive Protoplanetary Disk in the Main Accretion Phase
• Collapse and Fragmentation of Rotating Magnetized Clouds. II. Binary Formation and Fragmentation of First Cores
• Directions of Outflows, Disks, Magnetic Fields, and Rotation of YSOs in Collapsing Molecular Cloud Cores
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• Simulating star formation in molecular cores II. The effects of different levels of turbulence
• Multiple protostellar systems. I. A deep near infrared survey of Taurus and Ophiuchus protostellar objects
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• Second Core Formation and High Speed Jets: Resistive MHD Nested Grid Simulations
• First MHD Simulation of Collapse and Fragmentation of Magnetized Molecular Cloud Cores
• Evolution of Rotating Molecular Cloud Core with Oblique Magnetic Field
• A Near-Infrared Multiplicity Survey of Class I/Flat-Spectrum Systems in Six Nearby Molecular Clouds
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• An Infrared Multiplicity Survey of Class I/Flat-Spectrum Systems in the Rho Ophiuchi and Serpens Molecular Clouds
• Stability of Dynamically Collapsing Gas Sphere
• Global Nonradial Instabilities of Dynamically Collapsing Gas Spheres
• The Formation of Population III Binaries

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