Informazioni sull’evento


Coffee talks

Monday 05/06/2023 @ 14:30, Sala riunioni quarto piano e on-line (

Filippo Maccagni (ASTRON/INAF-OAC), "MeerKAT Ultra-Deep neutral hydrogen observations in Nearby Galaxies"

In the first part of my talk, I will present results from the ongoing 1650 hours MHONGOOSE survey. This survey is observing the neutral hydrogen (HI) in 30 nearby disk and dwarf galaxies with the MeerKAT radio synthesis telescope to search for signatures of cold gas accretion. A number of galaxies have now been observed to full depth, routinely reaching column densities just below 10^18 cm^-2 at resolutions of a kpc or less. We find a large variety of low-column density features in and around these galaxies, including low-column density clouds, signs of interaction with low-mass (10^6 MHI) dwarf galaxies, and complex distributions of extra-planar gas near the target galaxies. I will demonstrate the great potential of MHONGOOSE in studying the delicate balance between gas accreted from the intergalactic medium and material expelled from the disk that regulates star formation, thus providing novel information on the evolution of galaxies from low-surface brightness dwarfs to massive spirals. In the second part of my talk, I will present the MeerKAT survey I developed, MAGNHIFFIC: MeerKAT AGN HI feeding and feedback investigation close-by. This project studies the processes of feeding and feedback in 33 nearby AGN (<50 Mpc) with different energetic outputs, ages, hosts and environments. It leverages the sensitive MeerKAT HI observations to simultaneously probe, for the first time, the small scales near the black hole, the larger scales of the galactic disks and the environments of these AGN. In particular, I will focus on the analysis of the interplay between the radio jets and the gaseous multi-phase ISM in two nearby powerful radio AGNs, Fornax A and Centaurus A.