Galaxy evolution along the Cosmic Web

Tue, April 28, 2015

No galaxy is an island, and the evolutionary fate of these systems is often inextricably linked to their environment. This relationship is well understood at local scales; but what role do cosmic filaments play in the assembly of mass? Do galaxies in voids evolve differently to galaxies in clusters? These fundamental questions require not only detailed observations, but also thorough catalogues of large scale structure.
We have put together one such catalogue by combining data from the Galaxy And Mass Assembly (GAMA) survey and a modified minimal spanning tree (MST) algorithm. This catalogue classifies galaxies as belonging to filaments and voids, as well as a third class of interstitial structures called `tendrils,' which bridge the gap between filaments, or extend out into voids. We then use this catalogue to look for trends in the observational properties of galaxies in different environments; namely in their morphology, stellar content, and energy output. We further extend our analysis by looking at how the star formation rates of galaxies correlate with their placement along filaments; from their outskirts to their most central cores.