首页|数据的频域分析和望远镜自动控制——以中性氢观测实验为例

数据的频域分析和望远镜自动控制——以中性氢观测实验为例

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氢元素是宇宙中占比最高的重子物质,其中大部分以氢原子的形式存在.中性氢原子波长为21cm的超精细结构谱线,即中性氢21cm线,是较强的射电天文源,可以反映宇宙重子物质的分布.这里我们介绍在中山大学3.2米射电望远镜实验平台上开展的银河系中性氢21cm线观测实验,通过实际天文观测展示了从时域信号中获取动态频谱,以及通过时间和频率并道提高谱线信噪比的过程.同时,本文还介绍了射电望远镜的观测模式,并根据观测需要实现了望远镜自动巡天.在选做实验中,我们完成了银盘中性氢分布成图,并通过分析计算出太阳与银河系中心的距离,同时根据谱线红移计算出银河系旋转曲线.本文为"面向天文、物理和多个工科专业的射电望远镜实验平台"专题下篇,上篇是太阳流强时域变化实验,本专题为射电天文观测教学提供参考.
DATA FREQUENCY DOMAIN ANALYSIS AND TELESCOPE AUTOMATIC CONTROL:A CASE STUDY OF NEUTRAL HYDROGEN OBSERVATION EXPERIMENT
Hydrogen is the most abundant baryonic matter in the universe,with most of it ex-isting in the form of hydrogen atoms.The hyperfine line of neutral hydrogen atoms at 21cm wavelength is a strong radio source in the sky,making it a tool to probe the distribution of cosmic baryonic matter.In this paper,we introduce the experiment of galactic neutral hydrogen line observation conducted on the 3.2m radio telescope at Sun Yat-sen University(SYSU).The dynam-ic spectrum is achieved from the time-domain electromagnetic signals.The signal-to-noise ra-tio is increased by binning the timesteps and the spectra channels in the experiment.We also introduce the observation modes of radio telescopes,and achieve automatic sky survey on the 3.2m SYSU radio telescope.Sky map of neutral hydrogen distribution in our galaxy is genera-ted in an elective experiment.Based on the sky map,the distance between the sun and the ga-lactic center is estimated,and the galactic rotation curve is obtained based on the redshift of the lines.This paper,combined with the previous experiment on the temporal variation of so-lar radio flux introduced in the first paper of this series,provide references for practical radio astronomy teaching.

radio astronomyastronomical observation teachingautomated controlneutral hydrogengalactic survey

刘章韬、林浦、张靖毅、杨浩楠、高扬

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中山大学物理与天文学院天文系,广东 珠海 519082

射电天文学 天文观测教学 自动化控制 中性氢 银河系巡天

2024

物理与工程
清华大学

物理与工程

CSTPCD
影响因子:0.63
ISSN:1009-7104
年,卷(期):2024.34(6)