论文标题
使用GNILC测试宾果游戏21 cm模拟地图中的同步器模型和频率分辨率
Testing synchrotron models and frequency resolution in BINGO 21 cm simulated maps using GNILC
论文作者
论文摘要
为了恢复21 cm的氢线,必须将宇宙学信号与无线电频率下更强的前景贡献分开。宾果射电望远镜旨在测量21 cm线,并使用强度映射技术检测BAO。这项工作分析了GNILC方法的性能,并结合了功率谱辩护程序。该方法应用于模拟的宾果游戏任务,这是基于合作的先前工作。它比较了两个不同的同步加速器发射模型和不同的仪器配置,除了与辅助数据的组合外,还比较了在整个宾果游戏频带上优化前景删除和21 cm信号的恢复,并确定信号恢复的最佳频段数量。我们使用Planck Sky模型制作了前景排放图,使用烧瓶包装生成宇宙学HI发射图,并根据仪器设置创建热噪声图。我们将GNILC方法应用于模拟的天空图,以分离HI加热噪声贡献,并通过一种偏见的程序恢复了无噪声21 cm功率谱的估计值。我们发现使用80箱配置对HI信号进行了几乎最佳的重建,从而在所有频率3%的情况下导致功率谱重建平均误差。此外,我们的测试表明,GNILC对不同的同步加速器发射模型具有鲁棒性。最后,添加一个带有CBASS前景信息的额外通道,我们减少了21 cm信号的估计误差。我们以前的工作的优化,生产具有最佳渠道汇总数据的配置,在调试之前会极大地影响有关宾果硬件配置的决策。
To recover the 21 cm hydrogen line, it is essential to separate the cosmological signal from the much stronger foreground contributions at radio frequencies. The BINGO radio telescope is designed to measure the 21 cm line and detect BAOs using the intensity mapping technique. This work analyses the performance of the GNILC method, combined with a power spectrum debiasing procedure. The method was applied to a simulated BINGO mission, building upon previous work from the collaboration. It compares two different synchrotron emission models and different instrumental configurations, in addition to the combination with ancillary data to optimize both the foreground removal and recovery of the 21 cm signal across the full BINGO frequency band, as well as to determine an optimal number of frequency bands for the signal recovery. We have produced foreground emissions maps using the Planck Sky Model, the cosmological Hi emission maps are generated using the FLASK package and thermal noise maps are created according to the instrumental setup. We apply the GNILC method to the simulated sky maps to separate the Hi plus thermal noise contribution and, through a debiasing procedure, recover an estimate of the noiseless 21 cm power spectrum. We found a near optimal reconstruction of the Hi signal using a 80 bins configuration, which resulted in a power spectrum reconstruction average error over all frequencies of 3%. Furthermore, our tests showed that GNILC is robust against different synchrotron emission models. Finally, adding an extra channel with CBASS foregrounds information, we reduced the estimation error of the 21 cm signal. The optimisation of our previous work, producing a configuration with an optimal number of channels for binning the data, impacts greatly the decisions regarding BINGO hardware configuration before commissioning.