Galaxy groups as the ultimate probe of AGN feedback

Every major modern hydrodynamical simulation suite now includes a prescriptionfor AGN feedback to reproduce realistic populations of galaxies. However, thesesimulations generally do not offer much insight into the nature of feedback. Onthe other hand, the hot gas content of galaxy groups is highly sensitive to theimplemented feedback scheme: the predicted gas fraction differs by an order ofmagnitude from one simulation to another. Here we propose to observe a sample of40 galaxy groups exhibiting Xray emission on scales >12, with the aim ofproviding benchmark thermodynamic and gas fraction profiles out to R500 withoutrequiring any extrapolation. The proposed program will gather a well controlledsample of systems spanning an order of magnitude in mass 1e13 < M500 < 1e14 Mo. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]