mode gas in the outer halo is much lower. Without metal-line cooling, the temperature at radii smaller than $0.2R_{\rm vir}$ is much higher. With strong SN feedback or AGN feedback, a larger fraction of the gas is outflowing, the outflows are faster, and the peak in the fraction of the gas that is accreted in the hot mode peaks at a much larger radius (about $3R_{\rm vir}$ instead of $0.5-1.0 R_{\rm vir}$).

@Keres2011 have recently shown that some of the hot gas properties depend on the numerical technique used to solve the hydrodynamics. They did, however, not include metal-line cooling and feedback. They find that the temperatures of hot gas (i.e. $T>10^5$ K) around $10^{12-13}$ M$_\odot$ haloes are the same between the two methods, but that the median density and entropy of $10^{12}$ M$_\odot$ haloes is somewhat different, by less than a factor of two. These differences are comparable to the ones we find when using different feedback models. They also show that the radial velocities are different at small radii. Our results show that including metal-line cooling decreases the radial velocities, whereas including supernova or AGN feedback increases the radial velocities significantly. Even though there are some differences, the main conclusions of this work are unchanged. The uncertainties associated with the subgrid implementation of feedback and the numerical method are therefore unlikely to be important for our main conclusions.

Cold (i.e. $T \ll 10^5$ K) outflows are routinely detected in the form of blueshifted interstellar absorption lines in the rest-frame UV spectra of star-forming galaxies [e.g. @Weiner2009; @Steidel2010; @Rubin2010; @Rakic2011a]. This is not in conflict with our results, because we found that the outflowing gas spans a very wide range of temperatures and because the detectable UV absorption lines are biased towards colder, denser gas. Additionally, the results we showed are mass-weighted, but if we had shown volume-weighted quantities, the outflow fractions would have been lar