论文标题
观察电源:校准和位置误差对现实观察条件的影响
Observing the Reionization : Effect of Calibration and Position Errors on Realistic Observation Conditions
论文作者
论文摘要
观察宇宙黎明的红移21厘米信号和电离时代是观察性宇宙学的一项艰巨的努力。存在更明亮的天体前景和各种仪器系统的数量级的存在会增加这些观察结果的复杂性。这项工作提出了一条端到端管道,该管道处理敏感无线电观察的合成干涉数据。模拟的天空模型包括红移的21厘米信号和天体物理前景。已经模拟了校准误差和位置误差的效果,在红移21-CM功率谱的提取中已经模拟了。还研究了宇宙学信号的图像平面检测中误差的影响。已经证明了对SKA1-LOW,MWA和HERA等阵列配置的比较分析。在某些关于系统组件的性质的假设下,阵列的校准误差耐受性最佳地认为是$ \ sim 0.01 \%$用于检测信号。对于位置错误,$ \ gtrapprox 5 \ arcsec $的偏移使残留前景掩盖了目标信号。这些模拟还表明,在SKA-1中,低的表现比图像结构域中的其他模拟略有性能,而在功率谱域中的MWA也是如此。这是最早的研究之一,比较在相似的观察条件下进行检测宇宙信号的各种射电望远镜的性能。该端到端管道也可以扩展到色度梁,射频推断,具有光谱特征的前景等的研究效果。
Observation of the redshifted 21-cm signal from Cosmic Dawn and Epoch of Reionization is a challenging endeavor in observational cosmology. Presence of orders of magnitude brighter astrophysical foregrounds and various instrumental systematics increases the complexity of these observations. This work presents an end-to-end pipeline dealing with synthetic interferometric data of sensitive radio observations . The mock sky model includes the redshifted 21-cm signal and astrophysical foregrounds. The effects of calibration error and position error in the extraction of the redshifted 21-cm power spectrum has been simulated. The effect of the errors in the image plane detection of the cosmological signal has also been studied. A comparative analysis for array configurations like the SKA1-Low, MWA and HERA has been demonstrated. The calibration error tolerance of the arrays, under some assumptions about the nature of the systematic components, is optimally found to be $\sim 0.01\%$ for the detection of the signal. For position errors, an offset of $\gtrapprox 5\arcsec$ makes the residual foregrounds obscure the target signal. These simulations also imply that in the SKA-1 Low performs marginally better than the others in the image domain, while the same is true for MWA in the power spectrum domain. This is one of the first studies that compares performance of various radio telescopes operating under similar observing conditions towards detecting the cosmological signal. This end-to-end pipeline can also be extended to study effects of chromatic primary beam, radio frequency inferences, foregrounds with spectral features, etc.