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 recently published machine learning algorithm. This paper is part of a larger work to identify and characterize all AGN in the local Universe (z < 0.1) with the largest line-of-sight (los) column densities (NH), the so-called Compton-thick (NH,los ≥ 1024 cm−2) AGN. We modeled the X-ray spectra using two physically motivated models: UXClumpy and RXTorusD. Of the 11 AGN in our sample, we found 3 to be obscured with 22.7 < LogNH,los ≤ 23.0, 5 with 23.0 < LogNH,los ≤ 23.25, and 3 with 23.4 < LogNH,los ≤ 23.9, according to UXClumpy. Meanwhile, according to RXTorusD, we found 3 AGN to be obscured with 22.7 < LogNH,los ≤ 23.0, 4 with 23.0 < LogNH,los ≤ 23.4, and 4 with 23.85 < LogNH,los ≤ 23.96. Additionally, this work served as a comparison between UXClumpy and RXTorusD. We found broad agreement between the two, with 8 of 11 sources agreeing on the value of the photon index Γ, while only 5 of 11 sources agree on the NH,los value within the 90% confidence level.
Published April 10, 2026
| Version Published
Journal Article
Open
Compton-thick AGN in the NuSTAR Era. XI. Analyzing 11 CT-AGN Candidates Selected with Machine Learning
Creators
-
1.
Goddard Space Flight Center
-
2.
Southeastern Universities Research Association
-
3.
University of Minnesota
-
4.
University of Virginia
-
5.
Clemson University
-
6.
University of Bologna
- 7. INAF—Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti, 93/3, 40129 Bologna, Italy
-
8.
University of Maryland, Baltimore County
-
9.
California Institute of Technology
Abstract
Copyright and License
© 2026. The Author(s). Published by the American Astronomical Society.
Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Acknowledgement
The material is based upon work supported by NASA under award No. 80GSFC24M0006.
The authors thank the anonymous referee for the helpful comments that greatly improved our paper.
V.E.G. acknowledges funding under NASA contract 80NSSC24K1403.
Files
Silver_2026_ApJ_1001_94.pdf
Additional details
Related works
- Is new version of
- Discussion Paper: arXiv:2603.17077 (arXiv)
Funding
- National Aeronautics and Space Administration
- 80GSFC24M0006
- National Aeronautics and Space Administration
- 80NSSC24K1403
Dates
- Submitted
-
2025-10-20
- Accepted
-
2026-02-24
- Available
-
2026-04-07Published
Caltech Custom Metadata
- Caltech groups
- Space Radiation Laboratory , Division of Physics, Mathematics and Astronomy (PMA)
- Publication Status
- Published