Simulations of galaxy formation with radiative transfer: Hydrogen
  reionization and radiative feedback
  We carry out hydrodynamical simulations of galaxy formation that
simultaneously follow radiative transfer of hydrogen-ionizing photons, based on
the optically-thin variable Eddington tensor approximation as implemented in
the {\small GADGET} code. We consider only star-forming galaxies as sources and
examine to what extent they can yield a reasonable reionization history and
thermal state of the intergalactic medium at redshifts around $z\sim 3$. This
serves as an important benchmark for our self-consistent methodology to
simulate galaxy formation and reionization, and for future improvements through
accounting of other sources and other wavelength ranges. We find that star
formation alone is sufficient for reionizing the Universe by redshift $z\sim6$.
For a suitable choice of the escape fraction and the heating efficiency, our
models are approximately able to account at the same time for the one-point
function and the power spectrum of the Lyman-$\alpha$ forest. The radiation
field has an important impact on the star formation rate density in our
simulations and significantly lowers the gaseous and stellar fractions in
low-mass dark matter halos. Our results thus directly demonstrate the
importance of radiative feedback for galaxy formation. The spatial and temporal
importance of this effect can be studied accurately with the modelling
technique explored here, allowing more faithful simulations of galaxy
formation.
