论文标题

Sunyaev-Zel'Dovich效应的模拟差异观察:探测黑暗时代和电离时代

Simulated differential observations of the Sunyaev-Zel'dovich Effect: Probing the Dark Ages and Epoch of Reionization

论文作者

Takalana, Charles Mpho, Marchegiani, Paolo, Beck, Geoff, Colafrancesco, Sergio

论文摘要

这项工作提出了一种分析方法,用于研究来自黑暗时代(DA)和随后的电离时代(EOR)的宇宙学21cm背景信号。我们模拟星系簇的差异观察结果,以证明如何使用称为SZE-21CM的Sunyaev-Zel'Dovich效应的特定形式研究这些时代。这项工作产生了SZE-21厘米的模拟地图,并表明可以从低频无线电干涉仪(例如Reionization Array(HERA)的氢时代(HERA)和平方英里阵列(SKA))中提取SZE-21CM。为了模拟接近现实的场景,我们研究了宇宙差异噪声,并考虑到前景,热噪声和角度分辨率的影响,并考虑到我们的模拟观察结果。我们通过在星系簇样品上取平均值来进一步扩展这种探索,以减轻宇宙方差和仪器噪声的影响。还研究了点源污染的影响。最后,我们将此技术应用于边缘协作的结果,该技术在2018年报告了以78 MHz为中心的全球21cm背景信号的吸收功能。为了实现这项工作的目标,要解决的挑战包括由于宇宙变化,仪器噪声和点源污染而引起的错误。我们的方法证明了SZE-21CM作为DA和EOR的间接探针的潜力,我们得出的结论是,SZE-21CM的光谱特征来自我们的模拟观察结果产生的结果,这些结果接近先前的理论预测,并且可以使用SZE-21CM来测试ED EDGES检测的有效性。

This work presents an analytical approach for studying the cosmological 21cm background signal from the Dark Ages (DA) and subsequent Epoch of Reionization (EoR). We simulate differential observations of a galaxy cluster to demonstrate how these epochs can be studied with a specific form of the Sunyaev-Zel'dovich Effect called the SZE-21cm. This work produces simulated maps of the SZE-21cm and shows that the SZE-21cm can be extracted from future observations with low-frequency radio interferometers such as the Hydrogen Epoch of Reionization Array (HERA) and the Square Kilometre Array (SKA). In order to simulate near realistic scenarios, we look into cosmic variance noise, incorporate and take into account the effects of foregrounds, thermal noise, and angular resolution for our simulated observations. We further extend this exploration by averaging over a sample of galaxy clusters to mitigate the effects of cosmic variance and instrumental noise. The impact of point source contamination is also studied. Lastly, we apply this technique to the results of the EDGES collaboration, which in 2018 reported an absorption feature of the global 21cm background signal centred at 78 MHz. The challenges to be addressed in order to achieve the objectives of this work include errors that arise due to cosmic variation, instrumental noise and point source contamination. Our approach demonstrates the potential of the SZE-21cm as an indirect probe for the DA and EoR, and we conclude that the spectral features of the SZE-21cm from our simulated observations yield results that are close to prior theoretical predictions and that the SZE-21cm can be used to test the validity of the EDGES detection.

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