EXPLORING THE COSMIC REIONIZATION EPOCH IN FREQUENCY SPACE: AN IMPROVED APPROACH TO REMOVE THE FOREGROUND IN 21 cm TOMOGRAPHY

	EXPLORING THE COSMIC REIONIZATION EPOCH IN FREQUENCY SPACE: AN IMPROVED APPROACH TO REMOVE THE FOREGROUND IN 21 cm TOMOGRAPHY
	Wang, Jingying 1; Xu, Haiguang 1; An, Tao2 ; Gu, Junhua 3; Guo, Xueying 1; Li, Weitian 1; Wang, Yu 2; Liu, Chengze 1; Martineau-Huynh, Olivier 3,4,5; Wu, Xiang-Ping 3
刊名	ASTROPHYSICAL JOURNAL
	2013-02-01
卷号	763 期号:2 页码:1
关键词	cosmology: theory dark ages early universe methods: data analysis methods: statistical radio lines: general reionization first stars
英文摘要	With the intent of correctly restoring the redshifted 21 cm signals emitted by neutral hydrogen during the cosmic reionization processes, we re-examine the separation approaches based on the quadratic polynomial fitting technique in frequency space in order to investigate whether they work satisfactorily with complex foreground by quantitatively evaluating the quality of restored 21 cm signals in terms of sample statistics. We construct the foreground model to characterize both spatial and spectral substructures of the real sky, and use it to simulate the observed radio spectra. By comparing between different separation approaches through statistical analysis of restored 21 cm spectra and corresponding power spectra, as well as their constraints on the mean halo bias b and average ionization fraction x(e) of the reionization processes, at z = 8 and the noise level of 60 mK we find that although the complex foreground can be well approximated with quadratic polynomial expansion, a significant part of the Mpc-scale components of the 21 cm signals (75% for greater than or similar to 6 h(-1) Mpc scales and 34% for greater than or similar to 1 h(-1) Mpc scales) is lost because it tends to be misidentified as part of the foreground when the single-narrow-segment separation approach is applied. The best restoration of the 21 cm signals and the tightest determination of b and xe can be obtained with the three-narrow-segment fitting technique as proposed in this paper. Similar results can be obtained at other redshifts.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	LARGE-SCALE STRUCTURE ; CENTIMETER TOMOGRAPHY ; INTERGALACTIC MEDIUM ; NEUTRAL HYDROGEN ; POWER SPECTRUM ; POINT SOURCES ; HIGH-REDSHIFT ; 21-CM EPOCH ; H-I ; SKY
收录类别	SCI
语种	英语
WOS记录号	WOS:000313869800021
内容类型	期刊论文
源URL	[http://119.78.226.72/handle/331011/18037]
专题	上海天文台_VLBI研究室
作者单位	1.Shanghai Jiao Tong Univ, Dept Phys, Shanghai 200240, Peoples R China 2.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 3.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China 4.CNRS, IN2P3, Lab Phys Nucl & Phys Hautes Energies, F-75005 Paris, France 5.Univ Paris 06, F-75005 Paris, France
推荐引用方式 GB/T 7714	Wang, Jingying,Xu, Haiguang,An, Tao,et al. EXPLORING THE COSMIC REIONIZATION EPOCH IN FREQUENCY SPACE: AN IMPROVED APPROACH TO REMOVE THE FOREGROUND IN 21 cm TOMOGRAPHY[J]. ASTROPHYSICAL JOURNAL,2013,763(2):1.
APA	Wang, Jingying.,Xu, Haiguang.,An, Tao.,Gu, Junhua.,Guo, Xueying.,...&Wu, Xiang-Ping.(2013).EXPLORING THE COSMIC REIONIZATION EPOCH IN FREQUENCY SPACE: AN IMPROVED APPROACH TO REMOVE THE FOREGROUND IN 21 cm TOMOGRAPHY.ASTROPHYSICAL JOURNAL,763(2),1.
MLA	Wang, Jingying,et al."EXPLORING THE COSMIC REIONIZATION EPOCH IN FREQUENCY SPACE: AN IMPROVED APPROACH TO REMOVE THE FOREGROUND IN 21 cm TOMOGRAPHY".ASTROPHYSICAL JOURNAL 763.2(2013):1.