From the 1 of 10 linked papers with an AI index.
4 papers · 1 filter
Profile Analysis of the Multiwavelength 2.1-year Oscillations of PG 1553+113
P. Peñil, P. Peñil, N. Torres-Albà +8
We investigate the morphology of the oscillation profiles of the blazar PG~1553+113 in relation to its well-known 2.1 yr periodicity. We identify individual cycles in the …
X-ray Absorption Variability in NGC 1142: Another Constraint on the Nature of the Torus/Broad-Line Region in Active Galactic Nuclei
Isaiah S. Cox, Núria Torres-AlbÃ, Stefano Marchesi +5
The paper analyzes nine X‑ray observations of the active galaxy NGC 1142 over ~20 years to study changes in line‑of‑sight column density, using torus models to infer the geometry a…
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…
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…