Résumé / Abstract Seminaire_IAP
« The star formation histories of red galaxies »

Mike Hudson
Dept of Physics & Astronomy, University of Waterloo (Waterloo, Canada)

More than half of all the stars in the Universe today are found in "red and dead" galaxies. Extracting the star formation histories of these red galaxies from the "fossil record" is particularly challenging. Nevertheless, recent work by our group and others have shown that, while the most massive red galaxies have old stellar populations, the less massive galaxies are considerably younger. It is natural to wonder when and why the star formation stopped. Are the young ages the result of a single burst of star formation several billion years ago? Or are they the result of a light "frosting" of young stars superimposed on an older stellar population? I will focus on recent work that addresses this question by relating the star formation history of red galaxies to their dynamics. It turns out that this has important consequences for our understanding of the stellar and dark matter content of red galaxies. Finally, I will discuss physical mechanisms that may be responsible for quenching star formation, and evidence for or against such mechanisms.
vendredi 29 janvier 2010 - 11:00
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage