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Applied Physics 2022
低频SKA极化探究I：极化效应对EoR信号的影响
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Abstract:
探测再电离21 cm信号是存在困难的，即便在比EoR信号高四至五个数量级的前景干扰信号被去除后，由于相关仪器效应仍然能够对EoR信号的探测产生很严重影响。本文旨在通过低频SKA阵列探究极化效应对EoR信号的影响进行探究。在这里，我们在154~162 MHz频段下，在场中央2？ × 2？天区，通过模拟数据生成在不同极化STOKES参数下的EoR天图，并生成二维功率谱。通过对比我们发现在各种极化STOKES参数的作用下，其二维功率谱与总强度具有类似的结构，该研究可为后续极化效应的消除提供理论认知和实验基础。
Detecting the epoch of reionization (EoR) 21-cm signal is still very difficult due to the relevant instrument effects, even after the foreground interference that is four to five orders of magnitude higher than the EoR signal is removed. This paper is based on the low-frequency SKA array to ex-plore the influence of polarization effects on EoR signals. In the 2？ × 2？ sky area in the center of the field, we use simulation data to generate EoR sky map and two-dimensional power spectrum under different polarization STOKES parameters in the 154~162 MHz frequency band. The results indicate that two-dimensional power spectrum has a similar structure to total intensity under various polarization STOKES parameters, which can provide theoretical cognition and experimental basis for the elimination of subsequent polarization effects.
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