Detection of the significant impact of source clustering on higher-order statistics with DES Year 3 weak gravitational lensing data

Understand

We demonstrate and measure the impact of source galaxy clustering on higher-order summary statistics of weak gravitational lensing data.

• By comparing simulated data with galaxies that either trace or do not trace the underlying density field, we show this effect can exceed measurement uncertainties for common higher-order statistics for certain analysis choices.
• Source clustering effects are larger at small scales and for statistics applied to combinations of low and high redshift samples, and diminish at high redshift.
• We evaluate the impact on different weak lensing observables, finding that third moments and wavelet phase harmonics are more affected than peak count statistics.