论文标题
从贴花dr8功率谱和模拟目录验证的光度红移散射的自我校准
Self-calibration of photometric redshift scatter from DECaLS DR8 power spectrum and validation with simulated catalogues
论文作者
论文摘要
光度红移估计的不确定性是弱透镜宇宙学的主要系统学之一。自校准方法能够在不假设强大的先验的情况下降低这种系统。我们改进了最近提出的自我校准算法，以通过嘈杂的测量来增强稳定性和鲁棒性。改进的算法是根据根据贴纸DR8光度目录构建的模拟目录测量的功率光谱测试的。对于基准分析，具有5个相等宽的红移箱超过$ 0 <z <1 $和6个尺度上的6个频段，$ 100 \ leq \ ell <1000 $，我们发现改进的算法成功地重建了散布率和自动功率频谱，并在真正的红移架中以$ \ sim0.015 $ $ $ \ $ \ $ \ sim.44 $ \ sim.44 $ \ sim.44。与没有自我校准的照片 - $ z $相比，平均红移的偏见减少了50％以上，尤其是对于灾难性照片-Y $ z $错误的情况。贴花的重建结果DR8星系样品与模拟验证的期望一致。自启示代码可在https://github.com/penghui-hub/fp-nmf上公开获得。
The uncertainty in the photometric redshift estimation is one of the major systematics in weak lensing cosmology. The self-calibration method is able to reduce this systematics without assuming strong priors. We improve the recently proposed self-calibration algorithm to enhance the stability and robustness with the noisy measurement. The improved algorithm is tested on the power spectra measured from the simulated catalogues constructed according to DECaLS DR8 photometric catalogue. For the fiducial analysis with 5 equal-width redshift bins over $0<z<1$ and 6 bands over scales $100 \leq \ell<1000$, we find that the improved algorithm successfully reconstructs the scatter rates and the auto power spectrum in true redshift bins at the level of $\sim0.015$ and $\sim4.4$ per cent, respectively. The bias of the mean redshift is reduced by more than 50 per cent compared to the photo-$z$ without self-calibration, especially for the cases with catastrophic photo-$z$ errors. The reconstructed results of DECaLS DR8 galaxy sample are in line with the expectations from the simulation validation. The self-calibration code is publicly available at https://github.com/PengHui-hub/FP-NMF.
