External calibrator in global signal experiment for detection of the epoch of reionization  

作　　者：Yan Huang Xiang-Ping Wu Quan Guo Qian Zheng Bi-Ying Li Huan-Yuan Shan Ke-Jia Lee Hai-Guang Xu 

机构地区：[1]National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [2]Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China [3]Kavli Institute for Astronomy and Astrophysics,Peking University,Beijing 100871,China [4]School of Physics and Astronomy,Shanghai Jiao Tong University,800 Dongchuan Road,Shanghai 200240,China

出　　处：《Research in Astronomy and Astrophysics》2021年第10期17-26,共10页天文和天体物理学研究（英文版）

基　　金：supported by the Key Projects of Frontier Science of Chinese Academy of Sciences(Grant No.QYZDY-SSW-SLH022);the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB23000000);the National Key R&D Program of China(Grant No.2018YFA0404601)。

摘　　要：We present a conceptual design study of external calibrators in the 21 cm experiment towards detecting the globally averaged radiation of the epoch of reionization(EoR).Employment of external calibrator instead of internal calibrator commonly used in current EoR experiments allows removing instrumental effects such as beam pattern,receiver gain and instability of the system if the conventional three-position switch measurements are implemented in a short time interval.Furthermore,in the new design the antenna system is placed in an underground anechoic chamber with an open/closing ceiling to maximally reduce the environmental effect such as RFI and ground radiation/reflection.It appears that three of the four external calibrators proposed in this paper,including two indoor artificial transmitters and one outdoor celestial radiation(the Galactic polarization),fail to meet our purpose.Diurnal motion of the Galactic diffuse emission turns out to be the most probable source as an external calibrator,for which we have discussed the observational strategy and the algorithm of extracting the EoR signal.

关 键 词：cosmology:observations dark ages REIONIZATION radio lines:general methods:observational 

分 类 号：P159[天文地球—天文学]