Abstract
The fragmentation process of primordial-gas cores during prestellar collapse is studied using three-dimensional nested-grid hydrodynamics. Starting from the initial central number density of nc ∼ 103 cm-3, we follow the evolution of rotating spherical cores up to the stellar density nc ≃ 1022 cm-3. An initial condition of the cores is specified by three parameters: the ratios of the rotation and thermal energies to the gravitational energy ( β0 and α0, respectively), and the amplitude of the bar-mode density perturbation (AΦ). Cores with rotation β0 > 10-6 are found to fragment during the collapse. The fragmentation condition hardly depends on either the initial thermal energy α0 or amplitude of bar-mode perturbation AΦ. Since the critical rotation parameter for fragmentation is lower than that expected in first-star formation, binaries or multiples are also common for the first stars.
Original language | English |
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Pages (from-to) | 813-827 |
Number of pages | 15 |
Journal | Astrophysical Journal |
Volume | 677 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2008 Apr 20 |
Externally published | Yes |
Keywords
- Cosmology: theory
- Galaxies: formation
- Hydrodynamics
- Stars: formation
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science