Particle Astrophysics Seminar: Weak lensing with the Dark Energy Survey

  • Aug. 31, 2020, 2:00 pm US/Central
  • Alexandra Amon, Stanford

Abstract: I will present the current status of the cosmological weak lensing analysis from the Dark Energy Survey (DES) using its first three years of data, taken using the Dark Energy Camera on the 4m Blanco telescope at CTIO.  This analysis spans the full DES footprint, over 4000 sq. deg. of sky, with the final shear catalogue containing more than 100 million galaxies in riz photometric bands, constituting the most powerful weak lensing dataset to date. I will detail three systematics that weak lensing analyses are susceptible to – the redshift estimation, shear calibration and blending and modelling of the intrinsic alignment of galaxies, and the DES-Year 3 approach to account for these and deliver robust cosmological constraints. I’ll also summarise Lensing without borders, a cross-survey collaboration using cross-correlation with large-scale structure spectroscopic data to assess the consistency of weak lensing datasets.

For more information, please contact Yu-Dai Tsai at