Accretion and ejection in Hard X-ray selected AGN
Our work has been based on the selection at hard X-rays (>20 keV) of AGN. The hard X-ray selected sample of active galactic nuclei has been extracted from the INTEGRAL/IBIS all sky survey performed so far in the 20-100 keV band (Malizia et al. 2020; plus current update Malizia et al. 2022, in preparation). Most of these objects are RQ with a small percentage (10%) being RL. The hard X-ray selection has allowed us to provide an unbiased view of moderately high luminous, highly accreting AGN. This allow us to tackle different aspects of the accretion/ejection phenomena, probing radio emission from a variety physical mechanisms.
Giant radio galaxies and their duty cycle (GRACE)
Giant radio galaxies (GRG) are one of the most spectacular manifestation of astrophysical jets, showing plasma ejecta with an extension up to Mpc. However, the conditions allowings such a growth are still unclear, and may be linked to a particularly favourable environment, to peculiar accretion/ejection conditions allowing a very long and continuos radio activity, or to more than one radio cycle. The aim of the GRACE project is to study the radio duty cycle in a sample of giant radio galaxies selected from high energies (hard-X) catalogues produced by the INTEGRAL/IBIS and Swift/BAT space missions.
The emerging population of high-energy radio galaxies
The release of the 4th Fermi/LAT AGN catalogue, collecting more than a decade of observations, confirmed that blazars are the most represented class in the GeV sky (98% of sources). The remaining fraction (2%) includes other AGN, among which mostly radio galaxies, but also narrow line Seyfert 1, compact steep spectrum radio sources, and steep-spectrum radio quasars. The advent of new radio surveys such as the VLA Sky Survey (VLASS), and the Rapid ASKAP Continuum Survey (RACS), performed with the latest generation radio telescopes, is opening new possibilities on the classification and study of extragalactic gamma-ray sources, specially the underrepresented ones like radio galaxies.