FORMATION CRITERIA AND THE MASS OF SECONDARY POPULATION III STARS
- Department of Physics, Konan University, Okamoto, Kobe (Japan)
- Center for Computational Sciences, University of Tsukuba (Japan)
We explore the formation of secondary Population III (Pop III) stars under radiation hydrodynamic (RHD) feedback by a preformed massive star. To properly treat RHD feedback, we perform three-dimensional RHD simulations incorporating the radiative transfer of ionizing photons as well as H{sub 2} dissociating photons from a preformed star. A collapsing gas cloud is settled at a given distance from a 120 M{sub sun} Pop III star, and the evolution of the cloud is pursued including RHD feedback. We derive the threshold density depending on the distance, above which the cloud can keep collapsing owing to the shielding of H{sub 2} dissociating radiation. We find that an H{sub 2} shell formed ahead of an ionizing front works effectively to shield the H{sub 2} dissociating radiation, leading to the positive feedback for the secondary Pop III star formation. Also, near the threshold density, the envelope of gas cloud is stripped significantly by a shock associated with an ionizing front. By comparing the mass accretion timescale with the Kelvin-Helmholtz timescale, we estimate the mass of secondary Pop III stars. It turns out that the stripping by a shock can reduce the mass of secondary Pop III stars down to {approx}20 M{sub sun}.
- OSTI ID:
- 21333838
- Journal Information:
- Astrophysical Journal, Vol. 702, Issue 1; Other Information: DOI: 10.1088/0004-637X/702/1/480; Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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