Astronomy & Astrophysics Seminar: Investigating the links between galaxy structure and environment in the high redshift Universe

Abstract:

It has been long known that, in the local Universe, galaxy morphology is strongly related to environment. Furthermore, massive passive galaxies were observed to be 2 - 4 times more compact at z ~ 2 compared to the present day. Environment, in the form of mergers, halo mass and interactions, could explain the observed size increase as well as morphological transitions. I will present compelling evidence for a strong correlation between galaxy size and environment to z ~ 2, with massive quiescent galaxies from the highest density environments being ~ 50 per cent larger (on average) than those from the lowest density environments. Building upon these findings, I will show new results from a detailed analysis of stacked galaxy images. I will compare the light profiles obtained from stacking K-band images of quiescent galaxies in mass-environment bins, with the aid of both parametric and non-parametric methods. Drawing together recent findings, I will highlight the physical processes responsible for galaxies growing larger in dense environments.

Seminar Organizer: Prof. Rennan Barkana