Ratio of gas mass to dark matter within the virial radius of each halo, in units of the mean baryon fraction in the simulation. The circles, crosses, and dots show results from the N‐body/SPH simulation. The pentagons show results from a semianalytic model constrained to match the parameters of the simulation. The squares show results from a full semianalytic model. The circles show the total gas mass fraction, while the dots and crosses show the mass fractions of gas hotter and cooler than 12,000 K, respectively. The solid line shows the resolution limit of 32 gas particles.