54 citations · 267 across the 29 of their papers we have counts for
30 papers
Supermassive Black Hole Winds in X-rays -- SUBWAYS. VI. Interplay between the soft X-ray excess and ultra-fast outflows
V. E. Gianolli, P-O. Petrucci, S. Bianchi +42
We present a broadband, multiwavelength study of the interplay between the soft X-ray excess (SE), ultra-fast outflows (UFOs), and warm absorbers (WAs) in 21 active galactic nuclei…
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 +18
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-ray…
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…
A systematic search for AGN obscuration variability in the Chandra archive
Isaiah S. Cox, Núria Torres-Albà, 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…
Contemporaneous X-ray and Optical Polarization of EHSP Blazar H 1426+428
Anuvab Banerjee, Akash Garg, Divya Rawat +17
We present the first contemporaneous X-ray and optical polarimetric measurement of the extremely high synchrotron peaked (EHSP) blazar H 1426+428. The X-ray polarimetric observatio…
X-ray polarization observations of NGC 2110 with IXPE
I. Pal, S. Marchesi, N. Torres-Albá +6
X-ray polarimetric observations from the Imaging X-ray Polarimeter Explorer (IXPE) is an excellent tool for probing the geometry and dynamics of X-ray emitting corona in active gal…
Swift-XRT and NuSTAR Monitoring of Obscuration Variability in Mrk 477
N. Torres-Albà, Z. Hu, I. Cox +6
We present the analysis of 15 X-ray observations of Mrk 477, a nearby Seyfert 2 active galactic nucleus, with the objective to monitor its obscuring column density variability. The…
Chandra Follow-up Observations of Swift-BAT-selected AGNs III
Isaiah S. Cox, Núria Torres-Albà, Stefano Marchesi +5
The cosmic X-ray background (CXB) is dominated by the obscured and unobscured coronal light of active galactic nuclei (AGN). At energies below 10 keV, the CXB can be well explained…
An X-ray Significantly Variable, Luminous, Type 2 Quasar at z = 2.99 with a Massive Host Galaxy
Xiurui Zhao, Stefano Marchesi, Marco Ajello +8
We present a comprehensive X-ray analysis and spectral energy distribution (SED) fitting of WISEA J171419.96+602724.6, an extremely luminous type 2 quasar at = 2.99. The source…
Hydrogen Column Density Variability in a Sample of Local Compton-Thin AGN II
A. Pizzetti, N. Torres-Alba, S. Marchesi +7
We present the multi-epoch analysis of 13 variable, nearby (z<0.1), Compton-thin (22<logN_H<24) active galactic nuclei (AGN) selected from the 105-month BAT catalog. Analyzing all…
The High Energy X-ray Probe (HEX-P): Bringing the Cosmic X-ray Background into Focus
Francesca Civano, Xiurui Zhao, Peter Boorman +29
Since the discovery of the cosmic X-ray background (CXB), astronomers have strived to understand the accreting supermassive black holes (SMBHs) contributing to its peak in the 10-4…
The High Energy X-ray Probe (HEX-P): The Circum-nuclear Environment of Growing Supermassive Black Holes
P. G. Boorman, N. Torres-Albà, A. Annuar +32
Ever since the discovery of the first Active Galactic Nuclei (AGN), substantial observational and theoretical effort has been invested into understanding how massive black holes ha…
Compton-thick AGN in the NuSTAR Era X: Analysing seven local CT-AGN candidates
Dhrubojyoti Sengupta, Stefano Marchesi, Cristian Vignali +14
We present the broad-band X-ray spectral analysis (0.6-50 keV) of seven Compton-Thick active galactic nuclei (CT-AGN; line-of-sight, l.o.s., column density cm) ca…
A New Mid-Infrared and X-ray Machine Learning Algorithm to Discover Compton-thick AGN
Ross Silver, Núria Torres-Alba, Xiurui Zhao +4
We present a new method to predict the line-of-sight column density (NH) values of active galactic nuclei (AGN) based on mid-infrared (MIR), soft, and hard X-ray data. We developed…
A Simple Method for Predicting Variability in Active Galactic Nuclei
Isaiah Cox, Nuria Torres-Alba, Stefano Marchesi +4
The unified model of active galactic nuclei (AGN) includes a toroidal obscuring structure to explain the differences between Type I and Type II AGN as an effect of inclination angl…
Hydrogen Column Density Variability in a Sample of Local Compton-Thin AGN
N. Torres-Albà, S. Marchesi, X. Zhao +4
We present the analysis of multiepoch observations of a set of 12 variable, Compton-thin, local (z<0.1) active galactic nuclei (AGN) selected from the 100-month BAT catalog. We ana…
Identifying the 3FHL Catalog. VI. Swift Observations of 3FHL Unassociated Objects with Source Classification via Machine Learning
S. Joffre, R. Silver, M. Rajagopal +5
The Third Catalog of Hard Fermi Large Area Telescope Sources (3FHL) reports the detection of 1556 objects at E > 10 GeV. However, 177 sources remain unassociated and 23 are associa…
Compton-thick AGN in the NuSTAR Era. IX. A Joint NuSTAR and XMM-Newton Analysis of Four Local AGN
Ross Silver, Nuria Torres-Alba, Xiurui Zhao +7
We present the results of the broadband X-ray spectral analysis of simultaneous NuSTAR and XMM-Newton observations of four nearby Compton-thick active galactic nuclei (AGN) candida…
Revealing high-z Fermi-LAT BL Lacs using Swift and SARA data with photometric analysis
Y. Sheng, M. Rajagopal, A. Kaur +12
BL Lacertae (BL Lac) objects are a subclass of blazar, distinguished by their featureless optical spectrum. The featureless spectrum presents a challenge in measuring the redshift…
Compton-Thick AGN in the NuSTAR era VIII: A joint NuSTAR-XMM-Newton monitoring of the changing-look Compton-thick AGN NGC 1358
Stefano Marchesi, Xiurui Zhao, Núria Torres-Albà +18
We present the multi-epoch monitoring with NuSTAR and XMM-Newton of NGC 1358, a nearby Seyfert 2 galaxy whose properties made it a promising candidate X-ray changing look AGN, i.e.…
A multi-epoch X-ray study of the nearby Seyfert 2 galaxy NGC 7479: Linking column density variability to the torus geometry
Andrealuna Pizzetti, Nuria Torres-Alba, Stefano Marchesi +3
Active galactic nuclei (AGN) are powered by accreting supermassive black holes, surrounded by a torus of obscuring material. Recent studies have shown how the torus structure, form…