The effect of feedback from galaxy formation on the Lyman-alpha forest (Theuns et al 2002).
The top panels show the density (panels a & b) and temperature (panels c & d) for a slice through the simulation with feedback (panels a & c) and the simulation without feedback (panels b & d), at redshift 3. The simulation box is 5.0/h (co-moving) Mpc. The slice is chosen to go through the most massive object in the simulation. In the feedback simulation, hot bubbles of gas surround the galaxies. These tend to expand into the voids, thereby leaving the filamentary network of higher density regions unaffected. The four numbered horizontal lines (from top to bottom) are sight lines for which the Lyan-alpha spectrum, temperature, and density, are shown in the bottom panel (from left to right, offset for clarity). The feedback and no feedback cases are shown as blue and red lines, respectively (blue. Only the strongest lines are significantly affected by feedback.
The movie is here, shown are
log (temperature) log(density) log(HI abundance)
stars log(metallicity) log(HeII abundance)
Supernovae are shown as circles. Notice the reionization epochs of HI, HeI and HeII, and the increase in temperature during HI reionization.
The number in the stars frame is the redshift. The simulation box is 5Mpc/h on a side.