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Title: THE APPLICATION OF CONTINUOUS WAVELET TRANSFORM BASED FOREGROUND SUBTRACTION METHOD IN 21 cm SKY SURVEYS

Abstract

We propose a continuous wavelet transform based non-parametric foreground subtraction method for the detection of redshifted 21 cm signal from the epoch of reionization. This method works based on the assumption that the foreground spectra are smooth in frequency domain, while the 21 cm signal spectrum is full of saw-tooth-like structures, thus their characteristic scales are significantly different. We can distinguish them in the wavelet coefficient space easily and perform the foreground subtraction. Compared with the traditional spectral fitting based method, our method is more tolerant to complex foregrounds. Furthermore, we also find that when the instrument has uncorrected response error, our method can also work significantly better than the spectral fitting based method. Our method can obtain similar results with the Wp smoothing method, which is also a non-parametric method, but our method consumes much less computing time.

Authors:
 [1]; ; ;  [2]
  1. National Astronomical Observatories CAS, 20A Datun Road, Chaoyang District, Beijing (China)
  2. Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai (China)
Publication Date:
OSTI Identifier:
22140272
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 773; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; COSMOLOGY; DATA ANALYSIS; DETECTION; RED SHIFT; SPACE; SPECTRA; STARS

Citation Formats

Junhua, Gu, Haiguang, Xu, Jingying, Wang, Wen, Chen, and An Tao, E-mail: jhgu@bao.ac.cn. THE APPLICATION OF CONTINUOUS WAVELET TRANSFORM BASED FOREGROUND SUBTRACTION METHOD IN 21 cm SKY SURVEYS. United States: N. p., 2013. Web. doi:10.1088/0004-637X/773/1/38.
Junhua, Gu, Haiguang, Xu, Jingying, Wang, Wen, Chen, & An Tao, E-mail: jhgu@bao.ac.cn. THE APPLICATION OF CONTINUOUS WAVELET TRANSFORM BASED FOREGROUND SUBTRACTION METHOD IN 21 cm SKY SURVEYS. United States. doi:10.1088/0004-637X/773/1/38.
Junhua, Gu, Haiguang, Xu, Jingying, Wang, Wen, Chen, and An Tao, E-mail: jhgu@bao.ac.cn. Sat . "THE APPLICATION OF CONTINUOUS WAVELET TRANSFORM BASED FOREGROUND SUBTRACTION METHOD IN 21 cm SKY SURVEYS". United States. doi:10.1088/0004-637X/773/1/38.
@article{osti_22140272,
title = {THE APPLICATION OF CONTINUOUS WAVELET TRANSFORM BASED FOREGROUND SUBTRACTION METHOD IN 21 cm SKY SURVEYS},
author = {Junhua, Gu and Haiguang, Xu and Jingying, Wang and Wen, Chen and An Tao, E-mail: jhgu@bao.ac.cn},
abstractNote = {We propose a continuous wavelet transform based non-parametric foreground subtraction method for the detection of redshifted 21 cm signal from the epoch of reionization. This method works based on the assumption that the foreground spectra are smooth in frequency domain, while the 21 cm signal spectrum is full of saw-tooth-like structures, thus their characteristic scales are significantly different. We can distinguish them in the wavelet coefficient space easily and perform the foreground subtraction. Compared with the traditional spectral fitting based method, our method is more tolerant to complex foregrounds. Furthermore, we also find that when the instrument has uncorrected response error, our method can also work significantly better than the spectral fitting based method. Our method can obtain similar results with the Wp smoothing method, which is also a non-parametric method, but our method consumes much less computing time.},
doi = {10.1088/0004-637X/773/1/38},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 773,
place = {United States},
year = {2013},
month = {8}
}