| Abstract: |
Galaxy formation is a core astrophysical problem but theory remains incomplente. The physical basis for the mainstream, internal, AGN-driven feedback model is becoming increasingly at odds with the actual observed feedback strength from AGN and expected consequences of the proposed feedback model, which I briefly summarize. I will advocate a new type of feedback model, where gas accretion is prevented or reduced rather than outright blowout of gas inside-out. This outside-in (external), global and preventive feedback model is facilitated by the observed giant radio lobes that deposit most of their energy at distances far removed from host galaxies to heat up the nearby intergalactic medium to result in reduction or prevention of accretion of gas to nearby galaxies that otherwise would have been accreted unimpeded. I suggest that this external feedback model may be a cure for many current issues in galaxy formation simulations. |
