University of Heidelberg

Talk Details

Wednesday, November 3, 2010 - 3:15pm

Vincenzo Antonuccio-Delogu (INAF Italy):

"The self-feeding AGN"

Abstract. When a relativistic AGN jet enters the Interstellar Medium of its host galaxy, an internal backflow from the hotspot develops. We have studied in detail the circulation of gas inside the cocoon using numerical simulations, and developed a hydrodynamic model of this flow. We show that this circulation arises because of the presence of entropy and density gradients in two critical points: near the hot spot and the meridional plane of the cocoon. We have also performed a series of 3D numerical simulations of using and Adaptive refinement code (FLASH 3.2) to test this model and explore its observational consequences. The backflows supply the central AGN region with very low angular momentum gas, at rates of the order of $1-8, rm{M}_{odot}, rm{yr.}^{-1}$. These flows can reach the internal parsec-scale region of the BH, thus self-feeding the AGN itself. These backflows induce a compression of the circumnuclear dics, which can enhance their stellar formation. A comparison between the simulated spectra and observations of nearby young circumnuclear discs (Davies et al., 2007) suggest that these backflows could provide a self-regulatory mechanism of AGN activity, that is not directly controlled by, but possibly controls, the star formation rate within the central circumnuclear disc.Ref.: V.A.-D and J. Silk, MNRAS 405, 1303 (2010)

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