The alignment of galaxies and its impact in cosmology

by Georgiou Christos

Wednesday 29 Jan 2025, 13:00 → 14:00 Europe/Madrid

IFAE Seminar Room (In-person)

Galaxies in the universe are not randomly oriented but their shapes are set by the tidal gravitational. This intrinsic alignment manifests in a correlation between galaxy shapes and tracers of the matter density field. Because of this, intrinsic alignments are often regarded as a nuisance that contaminates the weak gravitational lensing signal. While it is important to accurately model and mitigate intrinsic alignments in this context, the alignment signal also contains valuable cosmological information due to its inherent connection to the gravitational field. At the same time, the intrinsic alignment signal is affected by galaxy evolution processes, such as mergers and AGN feedback. In this talk, I will discuss what we currently know about the dependence of the intrinsic alignment signal on several galaxy properties and how we might use this information to improve our modelling, extract cosmological information and learn more about galaxy evolution.