AGN feeding and feedback in Fornax A Kinematical analysis of the multi-phase ISM

We present a multi-wavelength study of the gaseous medium surrounding the nearby active galactic nucleus (AGN), Fornax A. Using MeerKAT, ALMA, and MUSE observations, we reveal a complex distribution of the atomic (H I), molecular (CO), and ionised gas in its centre and along the radio jets. By studying the multi-scale kinematics of the multi-phase gas, we reveal the presence of concurrent AGN feeding and feedback phenomena. Several clouds and an extended 3 kpc filament - perpendicular to the radio jets and the inner disk (r less than or similar to 4.5 kpc) - show highly-turbulent kinematics, which likely induces non-linear condensation and subsequent chaotic cold accretion (CCA) onto the AGN. In the wake of the radio jets and in an external (r greater than or similar to 4.5 kpc) ring, we identify an entrained massive (similar to 10(7) M-circle dot) multi-phase outflow (nu(OUT) similar to 2000 km s(-1)). The rapid flickering of the nuclear activity of Fornax A (similar to 3 Myr) and the gas experiencing turbulent condensation raining onto the AGN provide quantitative evidence that a recurrent, tight feeding and feedback cycle may be self-regulating the activity of Fornax A, in agreement with CCA simulations. To date, this is one of the most in-depth probes of such a mechanism, paving the way to apply these precise diagnostics to a larger sample of nearby AGN hosts and their multi-phase inter stellar medium.

Automated summary

This study presents a multi-wavelength analysis of the gaseous medium surrounding the nearby active galactic nucleus Fornax A, revealing a complex distribution of various gases. The research suggests the presence of concurrent AGN feeding and feedback phenomena, shedding light on the mechanisms that impact AGN activity. The findings provide evidence of a tight feeding and feedback cycle regulating the activity of Fornax A, with implications for a larger sample of AGN hosts and their interstellar medium.