嫦娥四号低频射电频谱仪2C数据对宇宙黑暗时代的探测能力分析  

Analysis of the Capability of Chang′E-4 Low Frequency RadioSpectrometer 2C Data in Detecting the Dark Ages

作　　者：焦康 王明远[2] 张同杰[1] 黄茂海[2] 平劲松[2] Jiao Kang;Wang Mingyuan;Zhang Tongjie;Huang Maohai;Ping Jinsong(Department of Astronomy,Beijing Normal University,Beijing 100875,China;National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China)

机构地区：[1]北京师范大学天文系,北京100875 [2]中国科学院国家天文台,北京100101

出　　处：《天文研究与技术》2021年第4期472-476,共5页Astronomical Research & Technology

基　　金：国家重点研发计划(2017YFA0402600);国家自然科学基金(11929301,61802428,11573006,11941003);中国科学院国际合作天文重点项目(GJHZ1867)资助

摘　　要：嫦娥四号着陆器搭载的低频射电频谱仪(Low Frequency Radio Spectrometer,LFRS)已成功开展观测,每月把观测数据传回地面,并且把经过一定预处理后的2C级别的频谱数据释放给科学团队。旨在评估该级别数据是否满足探测宇宙黑暗时代21 cm整体谱的要求,对生成的2C级别数据进行了长时间积分,并模拟仿真银河系前景射电辐射。通过对两套数据进行对比分析发现,2C数据减弱40~50 dB,几乎不包含银河系前景的远场辐射信号,这种大幅度的减弱进而影响了该载荷对宇宙黑暗时代的探测能力。The low-frequency radio spectrometer carried by Chang′E-4 lander has successfully carried out observation.The observational data are continuously sent back to the ground data center monthly.After certain pretreatment,the 2C level spectrum data is released to scientific teams.The main purpose of this article is to evaluate whether this level of data meets the requirements for detecting the sky-averaged 21 cm global spectrum of the cosmic dark ages.We make a long-term integration of the 2C level data,and simulate the reception of the Galactic foreground radio radiation by the lander.Through the comparison and analysis of the two sets of data,we find that the 2C data has been reduced by 40-50 dB,which almost does not contain the far-field radiation signal of the Galactic foreground.Such a large reduction will affect the detection ability of the payload for the dark ages.

关 键 词：低频射电频谱仪 嫦娥四号 黑暗时代 

分 类 号：P161[天文地球—天文学]