Hyperluminous quasars: The Masters of the Universe

In Webseminar by admin

24 Febbraio 2021, ore 11:00

Title: Hyperluminous quasars: The Masters of the Universe

Speaker: Luca Zappacosta da INAF-Osservatorio Astronomico di Roma

Abstract: High redshift hyperluminous (L_bol>10^47 erg/s) quasars are ideal targets to shed light on accretion/ejection mechanisms regulating the feedback processes needed in AGN/galaxy formation and co-evolutionary models.  I will present the analysis we are currently carrying out: a systematic, multi-wavelength study of the properties of the most luminous quasars in the Universe (z=2-3) spanning from UV/optical rest-frame to the X-ray band.  These sources, powered by Supermassive Black-Holes (SMBH) of >10^9 M_sun, exhibit a large range of nuclear obscuration, high Eddington ratios and widespread signs of outflows from nuclear to circumgalactic scales.  Hence they are sources where we expect quasar feedback to manifest in full force. In merger-driven formation scenarios such a feedback is responsible to drive the quasar lifecycle from the faint dust-obscured to the bright unobscured phases. In particular we discover that, despite the similarly high bolometric luminosity, the X-ray radiative output varies by > 1 dex and anti-correlates with the nuclear wind velocity inferred by the broad-lines, pointing to a link between the presence of nuclear winds and the quasar luminosity.  I will also present HYPERION a recently accepted XMM Multi-Year Heritage Programme to push our quasar view out the Epoch of Reionization. HYPERION aims at characterizing the accretion/ejection properties of the titans among the z>6 luminous quasars, i.e. those experiencing the most outstanding SMBH growth during the first billion years of cosmic evolution.