Description
Hyper-luminous quasars offer a unique opportunity to investigate the interplay between rapid SMBH growth, AGN feedback, and the evolution of massive galaxies at the peak epoch of quasar activity. In this talk, I will present recent results from the WISE/SDSS-selected hyper-luminous quasar survey (WISSH), a multi-wavelength observing program designed to study a representative sample of about 90 quasars at z ~ 2.5–3.5, with bolometric luminosities above 8 x 10^13 Lsun. By combining observations from millimeter wavelengths to hard X-rays, WISSH enables us to connect the nuclear properties of these extreme systems with the physical conditions of their host-galaxy interstellar medium and the presence of galaxy-scale outflows.
I will focus in particular on recent radio observations of WISSH quasars, which allow us to investigate the origin of radio emission and the dominant feedback channels in the most luminous accreting SMBHs. Despite their extreme luminosities, WISSH quasars show a remarkably low radio-loud fraction, suggesting that high accretion rates may preferentially favor radiatively driven feedback rather than powerful jet production. By comparing their radio properties with those of other AGN populations, we explore the relative contribution of AGN activity and star formation to the observed radio emission, and discuss the implications for the connection between accretion mode, radio output, and feedback in non-jetted hyper-luminous quasars.