Constraining black hole spin in PG 1535+547 amid complex multi-layered absorption
Madathil-Pottayil A, Walton DJ, Jiang J, Dauser T, Fabian A, Stern D, Gallo LC, Reynolds MT, Nardini E, Garcia JA (2026)
Publication Type: Journal article
Publication year: 2026
Journal
Book Volume: 546
Article Number: stag157
Journal Issue: 3
Abstract
We present a spectroscopic analysis of XMM–Newton and NuSTAR observations of the ‘complex’ narrow-line Seyfert 1 PG 1535+547 at redshift z = 0.038. These observations span three epochs: 2002 and 2006 with XMM–Newton alone, covering the 0.3−10 keV energy range, and a coordinated XMM–Newton and NuSTAR observation in 2016, covering the 0.3−60 keV energy range. The X-ray spectra across all epochs exhibit both neutral and ionized absorption, along with reflection featuresfrom the accretion disc, including a prominent Compton hump in the broadband data. Notably, the spectralshape varies across epochs. Our analysis suggests this variability is attributed to changes in both line-of-sight absorption and the intrinsic emission from PG 1535+547. The source is obscured by multiple layers of partially and/or fully covering neutral and ionized absorbers, with neutral column densities ranging from undetectable levels in the least obscured phase to ∼ 0.3−5 × 1023 cm−2 in the most obscured phase. A clear warm absorber is revealed during the least obscured phase. The continuum remains fairly consistent ( ≈ 2.2 ± 0.1) during the first two observations, followed by a substantial flux decrease (by a factor of ∼ 7 in the 2−10 keV band) in 2016 compared to 2006. The 2016 data indicate the source is in a reflection-dominated state during this epoch, with a reflection fraction of R > 7 and an X-ray source located at a height ≤ 1.72rg. Simultaneous fitting of the multi-epoch data suggests a rapidly rotating black hole with a spin parameter, a > 0.99. These findings imply that strong light-bending effects may account for the observed continuum flux reduction.
Authors with CRIS profile
Involved external institutions
University of Hertfordshire
United Kingdom (GB)
University of Cambridge
United Kingdom (GB)
Saint Mary's University
Canada (CA)
Ohio State University
United States (USA) (US)
National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF)
Italy (IT)
National Aeronautics and Space Administration (NASA)
United States (USA) (US)
California Institute of Technology (Caltech)
United States (USA) (US)
United Kingdom (GB)
University of Cambridge
United Kingdom (GB)
Saint Mary's University
Canada (CA)
Ohio State University
United States (USA) (US)
National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF)
Italy (IT)
National Aeronautics and Space Administration (NASA)
United States (USA) (US)
California Institute of Technology (Caltech)
United States (USA) (US)
How to cite
APA:
Madathil-Pottayil, A., Walton, D.J., Jiang, J., Dauser, T., Fabian, A., Stern, D.,... Garcia, J.A. (2026). Constraining black hole spin in PG 1535+547 amid complex multi-layered absorption. Monthly Notices of the Royal Astronomical Society, 546(3). https://doi.org/10.1093/mnras/stag157
MLA:
Madathil-Pottayil, A., et al. "Constraining black hole spin in PG 1535+547 amid complex multi-layered absorption." Monthly Notices of the Royal Astronomical Society 546.3 (2026).
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