arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2204.08158astro-ph.CO
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用AliCPT-1预报CMB透镜观测

Forecasts on CMB lensing observations with AliCPT-1

Jinyi Liu, Zeyang Sun, Jiakang Han, Julien Carron, Jacques Delabrouille, Siyu Li, Yang Liu, Jing Jin, Shamik Ghosh, Bin Yue, Pengjie Zhang, Chang Feng, Zhi-Qi H… 展开作者

Jinyi Liu, Zeyang Sun, Jiakang Han, Julien Carron, Jacques Delabrouille, Siyu Li, Yang Liu, Jing Jin, Shamik Ghosh, Bin Yue, Pengjie Zhang, Chang Feng, Zhi-Qi Huang, Hao Liu, Yi-Wen Wu, Le Zhang, Zi-Rui Zhang, Wen Zhao, Bin Hu, Hong Li, Xinmin Zhang

摘要:

AliCPT-1是中国第一个以高精度测量宇宙微波背景B模偏振为目标的CMB实验。该望远镜目前正在西藏部署,将在以90和150 GHz为中心的两个频段进行观测。我们预测了AliCPT-1的CMB透镜重构、透镜-星系以及透镜-CIB(宇宙红外背景)互相关信噪比(SNR)。我们考虑了两个不同综合观测时间的阶段,即“4模块 * 年”(第一阶段)和“48模块 * 年”(最后阶段)。对于透镜重建,我们使用三种不同的二次估计,即温度,偏振和最小方差估计,使用弯曲的天空几何。我们考虑到不均匀的命中计数的影响,以及由于不完整的天空覆盖的平均场偏差。在第一阶段中,我们的结果表明,150 GHz的信道是能够测量的透镜信号在$15σ$的意义与最小方差估计。在最后阶段,测量显著性将增加到$31σ$。我们还在谐波域中结合两个频率数据以优化SNR。结果表明,在l>800的倍数范围内,共加过程可以显著降低重建偏差。由于AliCPT-1最后阶段的偏振数据质量很高,EB估计器将在这一阶段主导透镜重建。我们还估计了AliCPT-1 CMB透镜与宇宙大尺度结构的其他示踪物之间的互相关的信噪比。对于它与DESI星系/类星体的互相关,我们报告了在0.05<z<2.1的4个红移仓的互相关SNR = 10-20。在第一阶段,总SNR约为$32$。在最后阶段,透镜-星系互相关可以达到SNR=52。

英文摘要:

AliCPT-1 is the first Chinese CMB experiment aiming for high precision measurement of Cosmic Microwave Background B-mode polarization. The telescope, currently under deployment in Tibet, will observe in two frequency bands centered at 90 and 150 GHz. We forecast the CMB lensing reconstruction, lensing-galaxy as well as lensing-CIB (Cosmic Infrared Background) cross correlation signal-to-noise ratio (SNR) for AliCPT-1. We consider two stages with different integrated observation time, namely "4 module*yr" (first stage) and "48 module*yr" (final stage). For lensing reconstruction, we use three different quadratic estimators, namely temperature-only, polarization-only and minimum-variance estimators, using curved sky geometry. We take into account the impact of inhomogeneous hit counts as well as of the mean-field bias due to incomplete sky coverage. In the first stage, our results show that the 150 GHz channel is able to measure the lensing signal at $15σ$ significance with the minimum-variance estimator. In the final stage, the measurement significance will increase to $31σ$. We also combine the two frequency data in the harmonic domain to optimize the SNR. Our result show that the coadding procedure can significantly reduce the reconstruction bias in the multiple range l>800. Thanks to the high quality of the polarization data in the final stage of AliCPT-1, the EB estimator will dominate the lensing reconstruction in this stage. We also estimate the SNR of cross-correlations between AliCPT-1 CMB lensing and other tracers of the large scale structure of the universe. For its cross-correlation with DESI galaxies/quasars, we report the cross-correlation SNR = 10-20 for the 4 redshift bins at 0.05<z<2.1. In the first stage, the total SNR is about $32$. In the final stage, the lensing-galaxy cross-correlation can reach SNR=52.

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