| 高红移类星体的21cm信号研究 |
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| 引用本文： | 向宏斌,马清波.高红移类星体的21cm信号研究[J].天文学报,2022,63(2):23-118. |
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| 作者姓名： | 向宏斌 马清波 |
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| 作者单位： | 1. 贵州师范大学物理与电子科学学院;2. 贵州省射电天文数据处理重点实验室贵州师范大学 |
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| 基金项目： | 贵州省科技计划项目([2020]1Y020)资助； |
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| 摘 要： | 利用高精度数值模拟的结果修正了高红移类星体(QSO)电离和加热中性气体的理论模拟,并预测了500m口径球面射电望远镜(Five-hundred-meter Aperture Spherical Telescope, FAST)观测QSO周围21 cm辐射的信号特征以及信噪比,得出如下结论:(1)红移z=8且光度与ULAS J1120+0641一致的QSO在FAST望远镜视场下的21 cm频率谱有完整的HII区,但在z=10且较低QSO光度下的21 cm频率谱仅有一个小的凹陷;(2)光子有限旅行时间(Finite Light Travel Time, FLTT)效应明显改变高红移QSO的21 cm频率谱,使得较低频率端的过渡曲线明显比较高频率端陡;(3)使用FAST望远镜观测高红移QSO的21 cm辐射的信噪比非常高,最高可达～12,因此可以很好地识别HII区和FLTT效应.
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| 关 键 词： | 类星体:普通 HII区 星系际介质 宇宙学:宇宙黑暗时期 再电离 第一代恒星 |
| 收稿时间： | 2021/6/21 0:00:00 |
Study on 21 cm Signal of High Redshift Quasars |
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| XIANG Hong-bin,MA Qing-bo.Study on 21 cm Signal of High Redshift Quasars[J].Acta Astronomica Sinica,2022,63(2):23-118. |
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| Authors: | XIANG Hong-bin MA Qing-bo |
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| Institution: | School of Physics and Electronic Science, Guizhou Normal University, Guiyang 550025; School of Physics and Electronic Science, Guizhou Normal University, Guiyang 550025;Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing, Guizhou Normal University, Guiyang 550001 |
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| Abstract: | We use the results of high resolution numerical simulations to fix the theoretical model of high redshift quasars (QSO) ionizing and heating neutral gas, and predict the signal characteristics and signal/noise (S/N) ratios for Five-hundred-meter Aperture Spherical Telescope (FAST) to observe the 21cm radiation around QSO. Our conclusions are summarized as: (1) the 21cm frequency spectrum under the FAST field has full HII region for the QSO at $z=8$ and with luminosity similar to ULAS J1120+0641, while has only a small trough for the QSO at z=10 and with low luminosity; (2) the effect of Finite Light Travel Time (FLTT) obviously changes the 21cm frequency spectrum of high redshift QSOs, makes the transition curve at lower frequency much steeper than that at higher frequency; (3) the FAST telescope can observe the 21cm radiation of high redshift QSO with very high S/N ratio as high as ~ 12, thus can identify the HII regions and the FLTT effect. |
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| Keywords: | quasars: general HII regions intergalactic medium cosmology: cosmic dark ages reionization first stars |
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