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A WENO algorithm of the temperature and ionization profiles around a point source

文献类型:期刊论文

作者Qiu, Jing-Mei; Feng, Long-Long; Shu, Chi-Wang; Fang, Li-Zhi
刊名NEW ASTRONOMY
出版日期2007-07-01
卷号12期号:5页码:398-409
关键词cosmology : theory, gravitation, hydrodynamics methods : numerical, shock waves
英文摘要We develop a numerical solver for radiative transfer problems based on the weighted essentially nonoscillatory (WENO) scheme modified with anti-diffusive flux corrections, in order to solve the temperature and ionization profiles around a point source of photons in the reionization epoch. Algorithms for such simulation must be able to handle the following two features: (1) the sharp profiles of ionization and temperature at the ionizing front (I-front) and the heating front (T-front), and (2) the fraction of neutral hydrogen within the ionized sphere is extremely small due to the stiffness of the rate equations of atom processes. The WENO scheme can properly handle these two features, as it has been shown to have high order of accuracy and good convergence in capturing discontinuities and complicated structures in fluid as well as to be significantly superior over piecewise smooth solutions containing discontinuities. With this algorithm, we show the time-dependence of the preheated shell around a UV photon source. In the first stage the I-front and T-front are coincident, and propagate with almost the speed of light. In later stage, when the frequency spectrum of UV photons is hardened, the speeds of propagation of the ionizing and heating fronts are both significantly less than the speed of light, and the heating front is always beyond the ionizing front. In the spherical shell between the I- and T-fronts, the IGM is heated, while atoms keep almost neutral. The time scale of the preheated shell evolution is dependent on the intensity of the photon source. We also find that the details of the pre-heated shell and the distribution of neutral hydrogen remained in the ionized sphere are actually sensitive to the parameters used. The WENO algorithm can provide stable and robust solutions to study these details. (c) 2006 Elsevier B.V. All rights reserved.
WOS标题词Science & Technology ; Physical Sciences
类目[WOS]Astronomy & Astrophysics
研究领域[WOS]Astronomy & Astrophysics
关键词[WOS]COSMOLOGICAL RADIATIVE-TRANSFER ; ORDER FINITE-DIFFERENCE ; EFFICIENT IMPLEMENTATION ; 1ST GALAXIES ; HII-REGIONS ; REIONIZATION ; SCHEMES ; SIMULATIONS ; EVOLUTION ; TRANSPORT
收录类别SCI
语种英语
WOS记录号WOS:000245333800004
源URL[http://libir.pmo.ac.cn/handle/332002/15853]  
专题紫金山天文台_南极天文中心
作者单位1.Brown Univ, Div Appl Math, Providence, RI 02912 USA
2.Purple Mt Observ, Nanjing 210008, Peoples R China
3.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
4.Univ Arizona, Dept Phys, Tucson, AZ 85721 USA
推荐引用方式
GB/T 7714
Qiu, Jing-Mei,Feng, Long-Long,Shu, Chi-Wang,et al. A WENO algorithm of the temperature and ionization profiles around a point source[J]. NEW ASTRONOMY,2007,12(5):398-409.
APA Qiu, Jing-Mei,Feng, Long-Long,Shu, Chi-Wang,&Fang, Li-Zhi.(2007).A WENO algorithm of the temperature and ionization profiles around a point source.NEW ASTRONOMY,12(5),398-409.
MLA Qiu, Jing-Mei,et al."A WENO algorithm of the temperature and ionization profiles around a point source".NEW ASTRONOMY 12.5(2007):398-409.

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来源:紫金山天文台

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