The large-scale conformity of galaxies

The large-scale conformity of galaxies

The systematic exploration of environmental effects on galaxies has identified a correlation between the colors and star formation rates of objects separated over several megaparsecs. This phenomenon, termed large-scale conformity, indicates a possible large-scale synchronization of galaxy quenching and star formation activity, raising questions about the role of the cosmic web, the assembly history of dark matter halos, and pre-heating mechanisms in regulating galaxy evolution. I will present results from cosmological simulations suggesting that the environment around galaxy groups and clusters plays a key role in the conformity signal. The verification of these findings from observations has been scarce because most surveys are not designed for galaxy clusters and their large-scale environments. I will describe CHANCES, the CHileAN Cluster galaxy Evolution Survey, which will overcome previous survey limitations in this matter through deep and wide multi-object spectroscopy of galaxy clusters and their surroundings. In particular, observations with the CHANCES Low-z subsurvey, designed to target 50 clusters at z ≤ 0.07 with extensive spatial coverage out to five times their virial radius, can help us understand the origin of conformity in the local Universe.

Sebastián López
Colloquium Coordinator
DAS/UChile  – slopez@das.uchile.cl