Conferencias y seminarios
Jueves 10 de Mayo de 2018
Sala de Conferencias Federico Ristenpart (Camino El Observatorio 1515, Departamento de Astronomía, Edificio Central, piso 3, Las Condes, Santiago, Chile)
Dr. Ricardo Demarco
Departamento de Astronomía, Universidad de Concepción.
Galaxy pre-processing in substructures around galaxy clusters
RESUMEN: Galaxy clusters are the most massive cosmic structures, and they are fundamental in the study of the environmental drivers of galaxy evolution. In the LCDM paradigm, galaxy clusters are formed through the merger of smaller structures. For this reason, the study of galaxy properties in the infall regions of clusters is important to understand the connection between cluster and galaxy evolution. In particular, some authors find high fractions of quiescent galaxies in the infall regions, which suggests that a significant fraction of galaxies were quenched before entering the cluster, a scenario known as pre-processing. Motivated by this, we have embarked on a systematic study of the cluster infall regions using state-of-the-art simulations and large observing data-sets. Here we present preliminary results from the study of two z~0.4 clusters, drawn from the CLASH-VLT survey, and galaxy overdensities from EAGLE simulations. From the CLASH-VLT observations, we find little difference in the trends of the fractions of red and blue galaxies with luminosity and cluster-centric distance between the main cluster and the detected substructures. This suggests that star-formation quenching in galaxy clusters began during the assembly of their dark matter haloes, supporting the pre-processing scenario. Our preliminary analyses of the EAGLE simulations also suggest that pre-processing plays a decisive role in the evolution of the star-formation quenching in large-scale structures.
Rene A. Mendez
Comunicaciones DAS - FCFM