Galaxy evolution and galaxy environments

Galaxy evolution and galaxy environments


Our group is dedicated to the study of galaxy properties and the formation and evolution of galaxies as a function of the local environment in which they reside. Within this context, we focus our
observations on galaxies in galaxy clusters and galaxy groups, the mass overdensities that delineate the filamentary distribution of matter in the universe. Clusters of galaxies are the most massive,
gravitationally-bound structures known, and ideal laboratories to study the environmental processes that shape the galaxies we observe in the local universe. Those processes must be at the origin of some of the most prominent characteristics of clusters: the morphology-density relation and the red-sequence of galaxies incolor-magnitude space. These relationships are the manifestation of
the morphological changes of galaxies and the quenching of their star formation activity. Galaxy-galaxy and galaxy-intracluster medium interactions certainly play a role in that evolution, however, the details of where and when such transformations take place and which one dominates are still poorly understood.  A significant progress in this line of research, to answer some
of the outstanding questions regarding galaxy evolution, requires the use of state-of-the-art facilities equipped with the most advanced and versatile set of instruments, which our group has access to.

Our team uses panchromatic, spectrophotometric data obtained with ground- and space-based observatories such as the VLT, Magellan, Gemini, ALMA, HST, and Spitzer, to name some. With these data, we are able to obtain redshifts, magnitudes, colors, line indices, and other relevant information for galaxies to characterize in the best possible way their properties, such as the stellar and gas mass content, stellar population mix, metal abundances, average ages, and star formation histories, among others. We can also characterize their environment by estimating local densities, the amount of substructure, and the overall dynamical state and dark matter content of the structure under consideration.

The team in Concepcion is led by Dr. Ricardo Demarco (professor of the Department of Astronomy) and currently includes Dr. Pierluigi Cerulo (FONDECYT Fellow), Ms. Daniela Olave (Ph.D. student), Ms. Valentina Ojeda (M.S. student), Mr. Orlando Vasquez (M.S. student), Mr. Felipe Enriquez (B.Sc. in astronomy) and Mr. Mauricio San Martin (B.Sc. in astronomy). We are involved in major international collaborations with colleagues from the U.S.A., Canada, Europe and Australia. We also have important on-going collaborations with colleagues from other institutions in Chile, and of course with the group led by Prof. Neil Nagar from our Department of Astronomy at UdeC.