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

	A WENO algorithm of the temperature and ionization profiles around a point source
	Qiu, Jing-Mei ; Feng, Long-Long; Shu, Chi-Wang ; Fang, Li-Zhi
刊名	NEW ASTRONOMY
	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
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/15863]
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.