1 November 2012

Speaker: Ranga-Ram Chary (Caltech)

Title:How are Galaxies Fed?

Abstract:The growth of stellar mass in galaxies requires a food source. In the local Universe, this typically involves Galactic cannibalism, with the most violent, star-forming systems being gas-rich mergers. In the distant Universe, the picture is muddied due to the challenges associated with obtaining rest-frame optical morphologies and kinematic data. I will present evidence based on the strong detection of nebular emission that the feeding of gas in high redshift (z>4) galaxies is a quasi-continuous process. The stellar population properties in these galaxies suggests an unusual combination of physical conditions that are mimicked in 0.04% of galaxies in the local Universe which serve as excellent laboratories for the study of the distant Universe. Implications for reionization of the intergalactic medium at z>6 resulting from an improved understanding of high-z star-formation will also be briefly discussed.

Video of the Presentation (Talks can be viewed with RealPlayer. Free download is available from www.real.com )