A panchromatic study of galaxies near and far, caught in the dusty midst of transformation (Laurie Riguccini; Observatorio do Valongo, Brazil)

From June 08, 2016 13:15 until June 08, 2016 13:45

At Instituto de Astrofísica, Pontificia Universidad Católica, Vicuña Mackenna 4860, Santiago, Chile

Categories: Seminarios

One of the key questions of modern cosmology is how galaxies formed and how they evolved through cosmic time. The past decades have shown that most of the star formation and galaxy mass assembly occurred at moderate redshifts (1<z<3). However it is still not clear what are the mechanisms that dominate the mass assembly. This question is even more delicate ackowledging the fact that a non-negligible amount of star formation takes place in very dusty environments. Furthermore, it has been recently established that the contribution to the star formation rate density from ultra-luminous IR galaxies (ULIRGs; LIR>1012 LSun) increases with increasing redshift and even dominates beyond z=1.5. It becomes clear that these sources are key sites of star formation in the distant universe and hence play a key role in the mass assembly of the galaxies we see today. However, being highly affected by dust extinction, it can be quite challenging to properly quantify the star formation in these systems.

These high-z galaxies likely evolve into the passive, massive galaxies that we observe today preferentially in dense cluster environments. However, slow transformations are still going on today, likely triggered by the environment. Present-day early-type galaxies (ETGs) represent the massive end of local galaxies and contain most of the visible mass in the Universe. They have been traditionally assumed to have simple, static and old stellar populations. However, recent studies show that these galaxies could present a complex star formation history that may vary with the environment; these results are still subject to much debate.

In this talk we will cover two lines of research. (1) Firstly we will focus on high-redshifts dust-obscured galaxies to unveil their starburst/AGN connection and study their properties through a multi-wavelength analysis. (2) Secondly, we aim to probe the star formation activity in early-type galaxies in disturbed large-scale structure environments, i.e., dense regions with merging activity or in-falling subgroups.

With this work we seek to study the rapid-versus-slow transformation of galaxies and put into perspective the relationship between local galaxies and their high-z progenitors.