Résumé / Abstract Seminaire_IAP
« Galaxy Formation at High Redshift: Key Theoretical Issues »

Avishai Dekel
Hebrew Univ. (Jerusalem, Israël)

The standard cosmology of LCDM leads to robust theoretical predictions for the formation and evolution of massive galaxies at high redshift, in their most active phase. The picture that emerges form LCDM is consistent with the main observed features of high-redshift galaxies. The theory is being worked out using hydrodynamical cosmological simulations and analytic modeling.

According to the emerging picture, the evolution of the high-redshift galaxies is driven by cold streams from the cosmic web. The dense gaseous disks that form in the dark-halo centers fragment into giant clumps due to wild gravitational instability, and the star formation rate in these clumps follows the high accretion rate. Clump migration in the disk, combined with merging clumps that come with the streams, lead to the formation of a central bulge. The system of disk and bulge remains in a steady state for a few Gyr, in which the disk gas is consumed into stars and flows into the bulge while it is replenished by newly accreted gas. The cold streams may be detected as Lyman-alpha blobs. Open questions will be discussed.
vendredi 4 décembre 2009 - 11:00
Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage