The Evolution of the Baryon Distribution in the Universe from
  Cosmological Simulations
  The evolution of the baryon distribution in different phases, derived from
cosmological simulations, are here reported. These computations indicate that
presently most of baryons are in a warm-hot intergalactic (WHIM) medium (about
43%) while at z = 2.5 most of baryons constitute the diffuse medium (about
74%). Stars and the cold gas in galaxies represent only 14% of the baryons at z
= 0. For z < 4 about a half of the metals are locked into stars while the
fraction present in the WHIM and in the diffuse medium increases with a
decreasing redshift. In the redshift range 0 < z < 2.5, the amount of metals in
the WHIM increases from 4% to 22% while in the diffuse medium it increases from
0.6% to 4%. This enrichment process is due essentially to a turbulent diffusion
mechanism associated to mass motions driven by supernova explosions. At z = 0,
simulated blue (late type) galaxies show a correlation of the oxygen abundance
present in the cold gas with the luminosity of the considered galaxy that
agrees quite well with data derived from HII regions.
