With their sizes larger than 0.7 Mpc, Giant Radio Galaxies (GRGs) are the largest individual objects in the Universe. To date, the reason why they reach such enormous extensions is still unclear. One of the proposed scenarios suggests that they are the result of multiple episodes of jet activity. Cross-correlating the INTEGRAL+Swift AGN population with radio catalogues (NVSS, FIRST, SUMSS), we found that 22% of the sources are GRG (a factor four higher than those selected from radio catalogues). Remarkably, 80% of the sample shows signs of restarting radio activity. The X-ray properties are consistent with this scenario, the sources being in a high-accretion, high-luminosity state with respect to the previous activity responsible for the radio lobes.
@article{arxiv.1902.01657,
title = {Probing restarting activity in hard X-ray selected giant radio galaxies},
author = {G. Bruni and F. Ursini and F. Panessa and L. Bassani and A. Bazzano and A. J. Bird and E. Chiaraluce and D. Dallacasa and M. Fiocchi and M. Giroletti and L. Hernandez-Garcia and A. Malizia and M. Molina and L. Saripalli and P. Ubertini and T. Venturi},
journal= {arXiv preprint arXiv:1902.01657},
year = {2020}
}
Comments
To appear soon as a proceeding of the XXXth IAU General Assembly, Focus Meeting 3 "Radio Galaxies: Resolving the AGN phenomenon"