中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
SUBTRACTING FOREGROUNDS FROM INTERFEROMETRIC MEASUREMENTS OF THE REDSHIFTED 21 cm EMISSION

文献类型:期刊论文

作者Mao, Xiao-Chun
刊名ASTROPHYSICAL JOURNAL
出版日期2012
卷号744期号:1
关键词cosmology: theory diffuse radiation intergalactic medium methods: data analysis radio lines: general techniques: interferometric
英文摘要The ability to subtract foreground contamination from low-frequency observations is crucial to reveal the underlying 21 cm signal. The traditional line-of-sight methods can deal with the removal of diffuse emission and unresolved point sources, but not bright point sources. In this paper, we introduce a foreground cleaning technique in Fourier space, which allows us to handle all such foregrounds simultaneously and thus sidestep any special treatments to bright point sources. Its feasibility is tested with a simulated data cube for the 21 CentiMeter Array experiment. This data cube includes more realistic models for the 21 cm signal, continuum foregrounds, detector noise, and frequency-dependent instrumental response. We find that a combination of two weighting schemes can be used to protect the frequency coherence of foregrounds: the uniform weighting in the uv plane and the inverse-variance weighting in the spectral fitting. The visibility spectrum is therefore well approximated by a quartic polynomial along the line of sight. With this method, we demonstrate that the huge foreground contamination can be cleaned out effectively with residuals on the order of similar to 10 mK, while the spectrally smooth component of the cosmological signal is also removed, bringing about a systematic underestimate in the extracted power spectrum primarily on large scales.
收录类别SCI
语种英语
WOS记录号WOS:000298408300029
源URL[http://ir.bao.ac.cn/handle/114a11/6165]  
专题国家天文台_星系宇宙学研究部
作者单位Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
推荐引用方式
GB/T 7714
Mao, Xiao-Chun. SUBTRACTING FOREGROUNDS FROM INTERFEROMETRIC MEASUREMENTS OF THE REDSHIFTED 21 cm EMISSION[J]. ASTROPHYSICAL JOURNAL,2012,744(1).
APA Mao, Xiao-Chun.(2012).SUBTRACTING FOREGROUNDS FROM INTERFEROMETRIC MEASUREMENTS OF THE REDSHIFTED 21 cm EMISSION.ASTROPHYSICAL JOURNAL,744(1).
MLA Mao, Xiao-Chun."SUBTRACTING FOREGROUNDS FROM INTERFEROMETRIC MEASUREMENTS OF THE REDSHIFTED 21 cm EMISSION".ASTROPHYSICAL JOURNAL 744.1(2012).

入库方式: OAI收割

来源:国家天文台

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