ﻻ يوجد ملخص باللغة العربية
We examine the detailed physics of the feedback mechanism by relativistic AGN jets interacting with a two-phase fractal interstellar medium in the kpc-scale core of galaxies using 29 3D grid-based hydrodynamical simulations. The feedback efficiency, as measured by the amount of cloud-dispersal generated by the jet-ISM interactions, is sensitive to the maximum size of clouds in the fractal cloud distribution but not to their volume filling factor. Feedback ceases to be efficient for Eddington ratios P_jet/L_edd<10^-4, although systems with large cloud complexes ~50 pc require jets of Eddington ratio in excess of 10^-2 to disperse the clouds appreciably. Based on measurements of the bubble expansion rates in our simulations we argue that sub-grid AGN prescriptions resulting in negative feedback in cosmological simulations without a multi-phase treatment of the ISM are good approximations if the volume filling factor of warm phase material is less than 0.1 and the cloud complexes are smaller than ~25 pc. We find that the acceleration of the dense embedded clouds is provided by the ram pressure of the high velocity flow through the porous channels of the warm phase, flow that has fully entrained the shocked hot-phase gas it has swept up, and is additionally mass-loaded by ablated cloud material. This mechanism transfers 10% to 40% of the jet energy to the cold and warm gas, accelerating it within 10 to 100 Myr to velocities that match those observed in a range of high and low redshift radio galaxies hosting powerful radio jets.
AGN heating, through massive subrelativistic outflows, might be the key to solve the long-lasting `cooling flow problem in cosmological systems. In a previous paper, we showed that cold accretion feedback and, to a lesser degree, Bondi self-regulated
[abridged] Aims: We test the effects of re-orienting jets from an active galactic nucleus (AGN) on the intracluster medium in a galaxy cluster environment with short central cooling time. We investigate appearance and properties of the resulting cavi
Aims: We study the emission of molecular gas in 3C236, a FR II radio source at z~0.1, and search for the footprints of AGN feedback. 3C236 shows signs of a reactivation of its AGN triggered by a recent minor merger episode. Observations have also pre
We present 1-7 GHz high-resolution radio imaging (VLA and e-MERLIN) and spatially-resolved ionized gas kinematics for ten z<0.2 type~2 `obscured quasars (log [L(AGN)/(erg/s)]>~45) with moderate radio luminosities (log [L(1.4GHz)/(W/Hz)]=23.3-24.4). T
We present simulations of galaxy formation, based on the GADGET-3 code, in which a sub-resolution model for star formation and stellar feedback is interfaced with a new model for AGN feedback. Our sub-resolution model describes a multiphase ISM, acco