基于可见度的红移21厘米功率谱渐变网格估计（TGE）
The visibility based Tapered Gridded Estimator (TGE) for the redshifted 21-cm power spectrum
摘要：
本文提出了一种改进的基于可见度的渐变网格估计方法（TGE），用于散射天空信号的功率谱估计。为了减少计算量，视区被网格化，并通过卷积逐渐变细，以抑制望远镜视场外部区域的贡献。TGE还在内部估计噪声偏置，并将其减去以给出功率谱的无偏估计。对角功率谱$C_{\ell}$的二维TGE的早期版本进行了改进，然后扩展到获得21 cm亮温波动功率谱$P({\bf k})$的三维TGE。分析公式也提出了用于预测的分箱功率谱的方差。估计和方差预测验证使用模拟的$150 \, {\rm MHz}$ GMRT观测。我们发现，估计准确地恢复输入模型的1D球面功率谱$P(k)$和2D柱面功率谱$P(k_\perp,k_\parallel)$，预测的方差也是在合理的好协议与模拟。
英文摘要：
We present the improved visibility based Tapered Gridded Estimator (TGE) for the power spectrum of the diffuse sky signal. The visibilities are gridded to reduce the computation, and tapered through a convolution to suppress the contribution from the outer regions of the telescope's field of view. The TGE also internally estimates the noise bias, and subtracts this out to give an unbiased estimate of the power spectrum. An earlier version of the 2D TGE for the angular power spectrum $C_{\ell}$ is improved and then extended to obtain the 3D TGE for the power spectrum $P({\bf k})$ of the 21-cm brightness temperature fluctuations. Analytic formulas are also presented for predicting the variance of the binned power spectrum. The estimator and its variance predictions are validated using simulations of $150 \, {\rm MHz}$ GMRT observations. We find that the estimator accurately recovers the input model for the 1D Spherical Power Spectrum $P(k)$ and the 2D Cylindrical Power Spectrum $P(k_\perp,k_\parallel)$, and the predicted variance is also in reasonably good agreement with the simulations.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
