Heidelberg Joint Astronomical Colloquium

Speaker Naoki Yoshida
Title Simulating the structure formation in the Universe at low and high redshifts

I present the results from recent large supercomputer simulations of cosmic structure formation. I first explain the "standard" model of early structure formation and then show the results of ab initio simulations of the formation of the first stars and blackholes. Our recent radiation hydrodynamics simulation follows the growth of a primordial protostar through nuclear burning to main sequence. We show that the characteristic mass of the primordial stars is several times tens of solarmasses, to yield core-collapse supernovae at the end of their lives, rather than exploding as pair-instability supernovae. Implications for the Galactic chemical evolution are discussed. I then present the results from a cosmological hydrodynamic simulation of the formation of submillimeter galaxies. Our novel model reproduces virtually all the observed properties of high-redshift submillimeter galaxies. Finally, I present the results from a very low resolution cosmological simulation of large-scale structure formation. The simulation indeed employs zero particles. Instead it directly integrates the collisionless Boltzmann equation in six-dimensional phase space. It places a milestone in the history of cosmological simulations. I talk about the future.