10 papers
The hidden variability of the torus in local Active Galactic Nuclei: 20 years of Chandra, XMM-Newton, and NuSTAR observations
Vittoria Elvezia Gianolli, Nuria Torres-Alba, Stefano Marchesi +9
X-ray absorption variability in active galactic nuclei (AGN) provides key constraints on the structure and dynamics of the circumnuclear obscuring medium, the so-called torus. A fr…
Compton-thick AGN in the NuSTAR Era. XI. Analyzing 11 CT-AGN Candidates Selected with Machine Learning
Ross Silver, Nuria Torres-Alba, Stefano Marchesi +8
This work discusses the broadband X-ray spectral analysis of 11 candidate heavily-obscured active galactic nuclei (AGN) selected based on their infrared and X-ray properties by a r…
PACHA: Probing AGN Coronae with High-redshift AGN
Xiurui Zhao, Elias Kammoun, Marco Ajello +19
The X-ray emission of active galactic nuclei (AGN) is generally attributed to inverse Compton scattering of accretion-disk photons by hot electrons in a compact corona. In local AG…
Transient Relativistic Iron Emission Line from an X-ray Flaring Supermassive Black Hole
Xiurui Zhao, Marco Ajello, Francesca Civano +16
We report the discovery of the first transient relativistic iron Kα line in an Active Galactic Nucleus (AGN) J1047+5907. The line was detected 21.5 days (rest-frame) after an X-ra…
A systematic search for AGN obscuration variability in the Chandra archive
Isaiah S. Cox, Núria Torres-AlbÃ, Stefano Marchesi +5
The nature of the obscuring material in active galactic nuclei (AGN) can be studied by measuring changes in the line-of-sight column density, , over time. This can b…
Unveiling Obscured Accretion in the Local Universe
Indrani Pal, Stefano Marchesi, Ross Silver +9
Heavily obscured Active Galactic Nuclei (AGN), especially Compton-thick sources with line-of-sight column density () 10 cm, are critical to underst…