The Formation of Population III Binaries

Abstract

We explore the possibility for the formation of Population III binaries. The collapse of a rotating cylinder is simulated with a three-dimensional, high-resolution nested grid, assuming the thermal history of primordial gas. The simulations are done with dimensionless units, and the results are applicable to low-mass as well as massive systems by scaling with the initial density. We find that if the initial angular momentum is as small as $\beta \approx 0.1$, where $\beta$ is the ratio of centrifugal force to pressure force, then the runaway collapse of the cloud stops to form a rotationally-supported disk. After the accretion of the envelope, the disk undergoes a ring instability, eventually fragmenting into a binary. If the initial angular momentum is relatively large, a bar-type instability arises, resulting in the collapse into a single star through rapid angular momentum transfer. The present results show that a significant fraction of Pop III stars are expected to form in binary systems, even if they are quite massive or less massive. The cosmological implications of Population III binaries are briefly discussed.

Astrophysical Journal Letter, in press. 10 pages, 2 color figures, (full paper with high-resolution figures available at http://yso.mtk.nao.ac.jp/~saigo/papers/saigo2004a/saigo2004.pdf)

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Cited by in corpus (30)

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• Forming a Primordial Star in a Relic HII Region
• Radiative Feedback from high mass X-ray binaries on the formation of the first galaxies and early reionization
• The Formation of Population III Stars in Gas Accretion Stage: Effects of Magnetic Fields
• Where are the Fossils of the First Galaxies? I. Local Volume Maps and Properties of the Undetected Dwarfs
• Conditions for the Formation of First-Star Binaries
• Dust-cooling--induced Fragmentation of Low-metallicity Clouds
• On the First Generation of Stars
• Constraints on the small-scale power spectrum of density fluctuations from high-redshift gamma-ray bursts
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• Binary Formation with Different Metallicities: Dependence on Initial Conditions
• Effect of metallicity on the gravitational-wave signal from the cosmological population of compact binary coalescences
• Dissipation of Magnetic Flux in Primordial Star Formation: From Run-away Phase to Mass Accretion Phase
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• The Lack of Gamma-Ray Bursts from Population III Binaries
• Gravitational wave background from population III binaries
• Forming Pop III binaries in self-gravitating disks: how to keep the orbital angular momentum
• Long gamma-ray burst rate at very high redshift
• Carbon Rich Extremely Metal Poor Stars: Signatures of Population-III AGB stars in Binary Systems
• The First Galaxies and the Likely Discovery of their Fossils in the Local Group
• Growth of Massive Disk and Early Disk Fragmentation in the Primordial Star Formation
• VIRGO sensitivity to binary coalescences and the Population III black hole binaries
• Formation of Massive Black Holes in Globular Clusters
• Gravitational Fragmentation of Extremely Metal-poor Circumstellar Discs
• The Impact of a Supernova Explosion in a Very Massive Binary