Speaker
Description
The delicate balance between material accreting from the intergalactic medium and gas expelled from galaxies regulates their evolution. The accretion of gas onto their central supermassive black holes (SMBHs) and the subsequent ejection of highly energetic winds and jets (AGN feeding and feedback processes) play a crucial role in maintaining or disrupting this balance. The HI 21-cm line is an excellent tracer of his complex gas cycle, as low-density HI clouds (N$_{\rm HI} <10^{20}$ cm$^{−2}$) have been linked to both inflows fueling the SMBH and AGN outflows.
MAGNHIFFIC is an ongoing survey leveraging ultra-deep MeerKAT and VST observations to study feeding and feedback phenomena in 15 nearby jetted and radiative AGN spanning a wide range of ages, energetic outputs and environments. A primary challenge in this project is determining the nature of the atomic gas flows in these AGN: are they associated with stellar streams and tidal remnants, or do they represent condensations of pristine gas? Furthermore, how do HI flows contribute to sustaining the nuclear activity? By perfectly matching MeerKAT’s large field of view ($\sim 1$ deg$^2$) with deep OmegaCAM@VST optical photometry ($\mu_r \sim27$ mag arcsec$^{−2}$), we can clearly interpret the nature of the HI features and obtain a complete picture of the stellar properties of our targets and their companions. In this talk, I will focus on three MAGNHIFFIC AGN where deep MeerKAT and OmegaCAM@VST deep observations shed new light on their interaction history and the HI flows fueling the AGN.