Using angular two-point correlations to self-calibrate the photometric redshift distributions of DECaLS DR9

Understand

Calibrating the redshift distributions of photometric galaxy samples is essential in weak lensing studies.

• The self-calibration method combines angular auto- and cross-correlations between galaxies in multiple photometric redshift (photo-$z$) bins to reconstruct the scattering rates matrix between redshift bins.
• In this paper, we test a recently proposed self-calibration algorithm using the DECaLS Data Release 9 and investigate to what extent the scattering rates are determined.
• We first mitigate the spurious angular correlations due to imaging systematics by a machine learning based method.