Galaxy properties and the evolutionary stage of clusters of galaxies – Sandro Rembold (UFSM)
14 de novembro: 12:30 - 14:00
Stellar ages, morphologies and gas abundances of galaxies are sensitive to the environment: high local densities favour passive, spheroidal, gas-poor galaxies, producing a number of well-established radial gradients in clusters and groups of galaxies. Environmentally-driven processes shaping the star formation history of a galaxy are thought to be the key ingredient of this behavior. Even at large clustercentric distances, the stellar populations of cluster galaxies are distinct of galaxies in the field, suggesting that the star formation history of infalling galaxies is affected even before accretion in a cluster — i.e. galaxies are “pre-processed” in lower-mass haloes before infall. On the other hand, galaxy properties are also distinct between dynamically relaxed and unrelaxed clusters; for example, galaxies in unrelaxed clusters present a more “field-like” stellar population. In order to explain these differences, it has been argued e.g. that unrelaxed clusters present a more intense infall rate than relaxed clusters. In this talk I will present some observational results concerning the differences between properties of galaxies in clusters at distinct dynamic evolutionary stages and discuss the implications of these findings on galaxy evolution.