S319p.239 — On the consequences of a Virial star formation criterion and radiation hydrodynamics in simulations of high redshift galaxies

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Aug 10th at 6:00 PM until 6:00 PM

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Author(s): Valentin Perret1, Romain Teyssier1, Julien Devriendt3, Joakim Rosdahl2, Adrianne Slyz3

Institution(s): 1. Institute for Computational Science, 2. Leiden Observatory, 3. University of Oxford

The last decade has seen a data deluge coming from observational facilities targeting the young universe. These data has revealed that high redshift galaxies are substantially different from their local counterpart that populates the Hubble sequence. High redshift star-forming galaxies often display clumpy morphologies associated to disk-like kinematics with a high level of turbulence. Star formation essentially occurs in these giant massive clumps and is therefore a crucial step in the life of galaxies. Reproducing the fragmentation of high redshift disk galaxies in numerical simulations is mandatory if one wants to get a realistic picture of the Hubble sequence shaping. We present state-of-the-art parsec scale idealised simulations of high redshift analogue galaxies that resolve the supersonic turbulent and clumpy multi-phase interstellar medium. These simulations are performed with the adaptive mesh refinement code RAMSES (Teyssier et al. 2002) using its new radiation hydrodynamics module (Rosdahl et al. 2013). We are therefore able to model the radiative pressure from the young massive stars population settled in the star forming clumps which is suspected to play a subsequent role in the onset of outflowing gas in such galaxies. Furthermore, our model includes a star formation criterion inspired from molecular cloud simulations and which is based on a local analysis of the turbulent support of the gas clouds. The star formation efficiency associated to this approach is two order of magnitudes higher than the one using the standard density threshold and has therefore major implications for the evolution of the galaxy. We will review through a comparative study the consequences of using radiative transfer combined with such a Virial star formation criterion for the star formation history, the gas and stellar morphology of the disk and clumps as well as the properties of the galactic fountain induced by stellar feedback. A first set of simulation presents idealised disks evolved in isolation. A second set of simulations explores the case of a merging pair of idealised disks.