Radiative transfer effects during photoheating of the intergalactic medium

The thermal history of the intergalactic medium (IGM) after reionization is to a large extent determined by photoheating. Here we demonstrate that cal culations of the photoheating rate which neglect radiative transfer effects substantially underestimate the energy input during and after reionization , The neglect of radiative transfer effects results in temperatures of the IGM which are too low by a factor of 2 after He II reionization. We briefly discuss implications for the absorption properties of the IGM and the dist ribution of baryons in shallow potential wells.