3 papers
astro-ph.GA2026
Fooled by mass? Recovering the relation of quasars from their X-ray variability
Matilde Signorini, Andrea Sacchi, Bartolomeo Trefoloni +7
We measure the relation between the X-ray photon index and the Eddington ratio in unobscured type-1 quasars, using as parent sample the cross-match of the SDSS DR16Q…
astro-ph.HE2026
The X-ray-to-UV relation does not evolve in homogeneous quasar samples
G. Risaliti, E. Lusso, E. Nardini +6
We present a new, highly homogeneous quasar sample with X-ray and UV observations optimized to reliably estimate distances via the non-linear X-ray-to-UV relation. Cross-matching t…
astro-ph.GA2025
Low-Eddington ratio, changing-look active galactic nuclei: the case of NGC 4614
Elisabeta Lusso, Lapo Casetti, Marco Romoli +27
Active galactic nuclei (AGN) are known to be variable sources across the entire electromagnetic spectrum, in particular at optical/ultraviolet and X-ray energies. Over the past dec…