期刊
ASTROPHYSICAL JOURNAL
卷 831, 期 1, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.3847/0004-637X/831/1/86
关键词
dark ages, reionization, first stars; early universe; hydrodynamics; intergalactic medium; large-scale structure of universe; radiative transfer
资金
- National Science Foundation East Asian and Pacific Summer Institute Program [SP13041]
- U.S. NSF grant [AST-1009799]
- NASA grant [NNX11AE09G]
- NASA/JPL grant RSA [1492788, 1515294]
- NSF XSEDE grant [TG-AST090005]
- [NRF-2012K1A3A7A03049606]
- [NRF-2014R1A1A2059811]
- NASA [148581, NNX11AE09G] Funding Source: Federal RePORTER
Density inhomogeneity in the intergalactic medium (IGM) can boost the recombination rate of ionized gas substantially, affecting the growth of H II regions during reionization. Previous attempts to quantify this effect typically failed to resolve down to the Jeans scale in the preionization IGM, which is important in establishing this effect, along with the hydrodynamical back-reaction of reionization on it. Toward that end, we perform a set of fully coupled, radiation-hydrodynamics simulations from cosmological initial conditions, extending the mass resolution of previous work to the scale of minihalos. Pre-reionization structure is evolved until a redshift z(i) at which the ionizing radiation from external sources arrives to sweep an R-type ionization front supersonically across the volume in a few million years, until it is trapped on the surfaces of minihalos and converted to D-type, after which the minihalo gas is removed by photoevaporative winds. Small-scale density structures during this time lead to a high (>10) clumping factor for ionized gas, which hugely boosts the recombination rate until the structures are disrupted by the hydrodynamic feedback after similar to 10-100. Myr. For incoming stellar radiation with intensity J(21) in a 200. h(-1). kpc box with the mean density contrastd (alpha) over bar, the number of extra recombinations per H atom, on top of what is expected from homogeneously distributed gas, is given by 0.32[J(21)](0.12) [(1 + Z(i))/11]-(1.7) [1 + (delta) over bar](2.5). In models in which most of the volume is ionized toward the end of reionization, this can add more than one recombination per H atom to the ionizing photon budget to achieve reionization.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据