Measuring and modelling galaxy intrinsic alignment

IAP weekly specialised seminars / 19 April 2024
Danielle Leonard (School of Mathematics Statistics and Physics, Newcastle University, United Kingdom)
Characterising dark energy - the mysterious phenomenon driving the accelerating expansion of the Universe - is the holy grail of modern cosmology. Determining its nature using weak gravitational lensing is a primary science goal of Rubin Observatory’s Legacy Survey of Space and Time (LSST), the global flagship ground-based imaging survey due to commence in 2025. To achieve this, we need to control modelling uncertainty on the intrinsic alignment of galaxies - correlations in the observed shapes of galaxies due to local gravitational and astrophysical processes. Intrinsic alignment is believed to be caused by a combination of tidal effects, galaxy evolution, and environment, but the precise physical details are poorly understood. In this talk, I will discuss work toward improving our measurements and modelling of galaxy intrinsic alignment, to enable precision constraints on dark energy with LSST weak lensing.