18 papers
Extreme Variability Reveals How the Eddington Ratio Regulates Coronal Power in Active Galactic Nuclei
Arghajit Jana, Claudio Ricci, Franz E. Bauer +13
The bolometric luminosity () of active galactic nuclei (AGNs) is a key tracer of accretion physics, but its direct determination is often hindered by limited spectral…
VAR-PZnn: A machine-learning framework for AGN photometric redshifts using color and variability-based features
S. Satheesh-Sheeba, P. Sánchez-Sáez, R. J. Assef +39
Photometric redshift estimation for active galactic nuclei (AGNs) remains a fundamental challenge for current and upcoming large-scale photometric surveys. Traditional spectral ene…
A New Member of the Fast and Furious Family: A Relativistic and Time-Variable UV Outflow in a Luminous Quasar
Lucas M. Seaton, Patrick B. Hall, Liliana Flores +20
We report the fastest quasar outflow first detected in the ultraviolet, via variable C IV and Si IV absorption at outflow velocities km s to at least km…
CIV wind properties of the SDSS-V X-ray selected quasars: strong optical-to-UV emission is key regardless of X-ray strength
Amy L. Rankine, David Homan, James Aird +25
We present an investigation of the rest-frame optical/UV and X-ray properties for a sample of 3027 X-ray selected quasars between detected in the deepest Spec…
4MOST ChANGES: Catalog of high-redshift quasar candidates (4.5 < < 7) selected with SED fitting
T. Mkrtchyan, C. Mazzucchelli, R. J. Assef +12
The identification of high-redshift quasars () is critical for studying the early Universe, supermassive black hole growth, and cosmic reionization. Most known high-redshi…
VAR-PZ: Constraining the Photometric Redshifts of Quasars using Variability
S. Satheesh-Sheeba, R. J. Assef, T. Anguita +33
The Vera C. Rubin Observatory LSST is expected to discover tens of millions of new Active Galactic Nuclei (AGNs). The survey's exceptional cadence and sensitivity will enable UV/op…