Active Galactic Nuclei XVI: A Sea of Discoveries

The AGN Luminosity Function at z~4 from the QUBRICS and DESI surveys

Not scheduled

20m

Sala Conferenze presso Autorità di Sistema Portuale (Brindisi)

Poster + Flash talk S7 - The Early Growth of Supermassive Black Holes: Examining the formation, growth rates, and census of SMBHs in the high-redshift universe (z>6) and their role in cosmic reionization

Speaker

Andrea Grazian (Istituto Nazionale di Astrofisica (INAF))

Description

Studying AGN population at high redshifts is crucial to understanding
supermassive black hole (SMBH) formation and evolution, the
intergalactic medium (IGM), and cosmological reionization. One of the
most important observational indicators for the evolution of the AGN
population is the AGN Luminosity Function, which has been the subject
of intense study and revision in recent years. We present here a
significantly extended and more complete determination of the AGN
Luminosity Function at redshift z~4 thanks to the QUBRICS and DESI
spectroscopic surveys, with the addition of recent JWST data. This
study compiles the most comprehensive AGN Luminosity Function to date,
spanning a wide range of over ten magnitudes in UV luminosity (from
M1450=-30.0 to -18). The combined data-sets provide the most stringent
constraints to date on the AGN Luminosity Function at z~4. These new
results confirm that z~4 AGNs provide the bulk of the ionizing photons
measured in the UV background, and they are vital for studying the
redshift evolution of AGNs and constraining theoretical models of SMBH
seeding and evolution. The extended and precisely known z~4 Luminosity
Function serves as a crucial benchmark for theoretical models of AGN
and for making accurate predictions for future wide-area imaging
surveys (e.g., Euclid, Vera Rubin LSST, and Roman).