Galaxy Cluster Outskirts: structure formation in the making

Speaker

Ulrike Kuchner
University of Nottingham (UK)

Abstract

Comprehending galaxy evolution and structure formation must include the environmental history of a galaxy over a lifetime spent in a hierarchically assembling environment: as part of filaments, groups and assembled into clusters. Our work focuses on processes acting before and during galaxy accretion into clusters. This comprises tracing cluster assembly in hydrodynamical zoom-in simulations from the ThreeHundred project to describe the collapse and feeding via filaments and groups from the cosmic web. By tracking halos through time and measuring their environmental proxies, we can create a benchmark to compare observational signatures to. Understanding "filament galaxies" as a combination of group-, backsplash- and filament galaxies, that each affect star formation according to their unique environment, helps to reconstruct the different modes of pre-processing. Transforming the simulations into mock-observations also allows us to forecast the reliability of filament finding -- an important asset given the difficulties of identifying cosmic web structures in redshift space. This has been crucial for getting ready for the WEAVE Wide-Field Cluster Survey (WWFCS), starting later this year, which will observe many thousands of galaxies in clusters and their filamentary outskirts out to five times their viral radii with the new multi-object spectrograph WEAVE. Over the next five years, we will quantify cluster outskirts and study the impact of structure growth on the galaxy population, which includes determining whether significant pre-processing accelerates the quenching of star formation.

Date and Time

September 2 2021
4pm KST (= 7am UTC)

Recording

Link to the recording on Youtube