Feeding and Feedback in Fornax A: a multiwavelength kinematical analysis
Filippo Maccagni (Kapteyn Astronomical Institute)
Tuesday 09/11/2021 @ 14:00, Sala IV piano Battiferro
The energy ejected by an active galactic nucleus (AGN) can displace the gas in a galaxy, prevent it from cooling and quench star formation, playing a crucial role in the evolution of galaxies. No consensus has yet been reached on how these disruptive, but short and stochastic events may influence the host galaxy throughout its lifetime. Radio AGN may be key to understand this, because by measuring the age of the synchrotron AGN emission it is possible to relate the timescales of the nuclear activity to the ones of the dynamical and star formation history of the host galaxy. In this talk, I will show new MeerKAT 1.4 GHz and SRT 6 GHz observations of Fornax A which allowed us to unlock the history of the nuclear activity of this source, revealing its rapid flickering (on scales of 1-10 Myr). The synergy between the radio continuum information and multi-wavelength spatially resolved spectral line observations is crucial to understand the impact of the recursive activity of AGN. The distribution and kinematics of the neutral, molecular and ionised gas of Fornax A (revealed by MeerKAT, ALMA and MUSE, respectively) reveal different regions in the centre with strong deviations from the rotating kinematics of the stellar body. Their kinematical properties suggest that several clouds are have outflowing motions, while others are likely condensing rapidly and falling back towards the AGN. I will show how in Fornax A events of feeding and feedback in the multi-phase gas over different scales (from ~500 pc to 6 kpc) appear to co-hexist in space and time explaining the rapid recurrent activity of the AGN.