Mitigating Systematic Errors in Angular Correlation Function Measurements from Wide Field Surveys

Understand

We present an investigation into the effects of survey systematics such as varying depth, point spread function (PSF) size, and extinction on the galaxy selection and correlation in photometric, multi-epoch, wide area surveys.

• We take the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS) as an example.
• Variations in galaxy selection due to systematics are found to cause density fluctuations of up to 10% for some small fraction of the area for most galaxy redshift slices and as much as 50% for some extreme cases of faint high-redshift samples.
• This results in correlations of galaxies against survey systematics of order $\sim$1% when averaged over the survey area.