NAOC Open IR  > 射电天文研究部
Foreground removal of 21 cm fluctuation with multifrequency fitting
He, Li-Ping1,2
2009-06-01
发表期刊RESEARCH IN ASTRONOMY AND ASTROPHYSICS
卷号9期号:6页码:653-664
摘要The 21 centimeter (21 cm) line emission from neutral hydrogen in the inter-galactic medium (IGM) at high redshifts is strongly contaminated by foreground sources such as the diffuse Galactic synchrotron emission and free-free emission from the Galaxy, as well as emission from extragalactic radio sources, thus making its observation very complicated. However, the 21 cm signal can be recovered through its structure in frequency space, as the power spectrum of the foreground contamination is expected to be smooth over a wide band in frequency space while the 21 cm fluctuations vary significantly. We use a simple polynomial fitting to reconstruct the 21 cm signal around four frequencies 50, 100, 150 and 200 MHz with an especially small channel width of 20 kHz. Our calculations show that this multifrequency fitting approach can effectively recover the 21 cm signal in the frequency range 100 similar to 200 MHz. However, this method doesn't work well around 50 MHz because of the low intensity of the 21 cm signal at this frequency. We also show that the fluctuation of detector noise can be suppressed to a very low level by taking long integration times, which means that we can reach a sensitivity of approximate to 10 mK at 150 MHz with 40 antennas in 120 hours of observations.
关键词Methods: Data Analysis Cosmology: Theory Observations Diffuse Radiation
收录类别SCI
语种英语
WOS记录号WOS:000267180100004
引用统计
文献类型期刊论文
条目标识符http://ir.bao.ac.cn/handle/114a11/8374
专题射电天文研究部
作者单位1.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
2.Chinese Acad Sci, Grad Univ, Beijing 100049, Peoples R China
推荐引用方式
GB/T 7714
He, Li-Ping. Foreground removal of 21 cm fluctuation with multifrequency fitting[J]. RESEARCH IN ASTRONOMY AND ASTROPHYSICS,2009,9(6):653-664.
APA He, Li-Ping.(2009).Foreground removal of 21 cm fluctuation with multifrequency fitting.RESEARCH IN ASTRONOMY AND ASTROPHYSICS,9(6),653-664.
MLA He, Li-Ping."Foreground removal of 21 cm fluctuation with multifrequency fitting".RESEARCH IN ASTRONOMY AND ASTROPHYSICS 9.6(2009):653-664.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[He, Li-Ping]的文章
百度学术
百度学术中相似的文章
[He, Li-Ping]的文章
必应学术
必应学术中相似的文章
[He, Li-Ping]的文章
相关权益政策
暂无数据
收藏/分享
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。