The turbulent dynamics of high-redshift disk galaxies (Andreas Burkert, 16/1/2024)
Channel: Academy of Athens
Date: 2024-01-16

Andreas Burkert 
Chair of Theoretical and Computational Astrophysics
Ludwig Maximilians University, Munich
 
Abstract:
 
The redshift two Universe ist one of the most interesting epochs of galaxy evolution. It is the era with the peak of the cosmic star formation rate. Between redshift 3 and 1 the total stellar mass density in galaxies increased from 15% to 70%. It is also the time of rapid galaxy assembly and the epoch where galaxy morphology was determined.

I will discuss recent results of the SINS survey, a Spectroscopic Imaging survey of z=2 galaxies in the near infrared with SINFONI. The SINS data shows star-forming galaxies with physical properties that are unparalleled in the z=0 Universe. Gas-rich, extended, fast rotating and highly turbulent disks have been found with an irregular surface density structure that is dominated by kpc-sized star-forming, massive clumps that might be the progenitors of globular clusters, supermassive black holes and bulges. Star formation rates are extreme. Strong radial gas flows through the disks into the galactic center are found, indicating a fast morphological transformation from extended disks to compact spheroidal structures. No signature of a dark matter component is found, despite the fact that at these redshifts dark halos should be more compact, dominating the rotation curves of extended disks.

These observations open a fascinating window into early galaxy evolution. They reveal a rich variety of dynamical processes that shape the Hubble sequence of galaxies and that at moment are far from being understood in details.