"The Fate of Stellar Yield: The Cycle of Baryons Across Cosmic Time"

Wednesday, April 6, 2016 - 11:00
AURA Lecture Hall
GONZALO DIAZ, National University of San Juan and CONICET, Argentina and Gemini South Visiting Astronomer
Talk Abstract: 

Chemical elements heavier than helium are produced by stars during their life and death. These metals are dispersed to the interstellar medium and they can reach intergalactic distances helped by galactic-scale winds. Eventually, they can flow back to a galaxy and the cycle starts again. This cycle is fundamental for galaxy formation and evolution because metals provide a cooling mechanism for the gas (hydrogen) that will form new stars. However, little is know about the fate of metals outside galaxies. 

One way to study metals outside galaxies is by means of metal absorption line systems in the spectra of background quasars. These systems have information about the circum-galactic and the intergalactic medium. Our work is to determine the origin of metal absorption systems by studying their environment and the galaxies that produce them. In particular, we search for galaxies near triply-ionized carbon C IV systems at redshift > 3. In this talk, I will present recent results that suggest that the mechanisms of dispersal of metals could have been more efficient at z~6 than at z<3. I will discuss the limitations of this result and I will present the current status of our search for the origin of C IV absorption systems.