Open Group Seminar: Roohi Dalal (Princeton University)

2:00–3:00 pm ERC 401

Host: Chihway Chang

Roohi Dalal (Princeton University) "Cosmology and Systematics from Hyper Suprime-Cam Year 3 Data"

The Hyper Suprime-Cam (HSC) survey is the deepest Stage III weak lensing experiment, going to ~26 mag with exquisite seeing. The depth and image quality achieved by HSC allow us to probe cosmology using weak lensing upto high redshifts, and these analyses serve as important preparatory studies for the next generation of weak lensing surveys. I will discuss our constraints on cosmological parameters using weak lensing cosmic shear power spectra measured from the Year 3 shear catalog of HSC, covering 416 square degrees of the northern sky. After giving a brief overview of our cosmological analysis, and our new constraint on the S8 parameter, I will focus on systematics that have been important and distinguishing factors in our analysis, including photometric redshift uncertainties, systematics from higher order PSF moments, and uncertainties in the modeling of baryonic feedback. I will show that we have made a number of conservative choices to ensure that our analysis is robust to these systematics and share some lessons learned that will enable future surveys to hopefully no longer be limited by such systematics.

Event Type


Aug 22