HLRB Project pr32re
The formation of massive star forming disks at high redshift
Max-Planck-Institute for Astrophysics
Proposing Institution
Max-Planck-Institute for Astrophysics
Project Manager
Dr. Thorsten Naab
Scheinerstr. 1
81679 München
Abstract
Recent high resolution observations by the IR-group at MPE in Garching revealed the existence of a new class of massive galaxies with rapidly star-forming disks at redshifts of z~2. The detailed formation mechanism of these galaxies is yet not understood. However, these galaxies are dominated by rotation and therefore likely to grow by smooth accretion of gas rather than by major mergers, which is surprising in the context of modern hierarchical cosmologies where mergers of subunits are supposed to drive galaxy formation. Low-resolution numerical studies have established the existence of high-flux 'cold streams' of gas arriving from large cosmological distances directly into the inner regions of dark matter halos, where galaxies presumably reside. Yet, those studies were not able to resolve the formation of the central galaxy and the observed intensity of star-formation in those systems. We propose to run a large number of high-resolution simulations of individual massive z~2 galaxies starting from cosmological initial conditions. We will use the N-body/SPH code Gadget to model the evolution of the dark matter, gas and stars, combined with physically-motivated recipes to model gas cooling, star formation and feedback from supernovae and black holes. Our goal is to understand the formation of high redshift disk-like galaxies with high star-formation rates comparable to observations, reproduce the observed high velocity dispersions and gas fractions, and study the interaction of the inflowing gas with the existing disk. We will strive to demonstrate the robustness of the results using a statistically significant sample of simulated systems.
