Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Faculty Publications Article Faculty Publications -Articles Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Creator An entity primarily responsible for making the resource Devanand, P.U.; Gupta, Alok C.; Wiita, Paul J.; Jithesh, V.; Gupta, Archana Title A name given to the resource X-Ray Spectral Variability of the TeV High-energy Peaked Blazar PG 1553+113 with XMM-Newton Date A point or period of time associated with an event in the lifecycle of the resource 01-01-2026 Source A related resource from which the described resource is derived Astrophysical Journal;Volume;1002;Issue;2;Article No.;157; Identifier An unambiguous reference to the resource within a given context <a href="https://doi.org/10.3847/1538-4357/ae5dc1" target="_blank" rel="noreferrer noopener">https://doi.org/10.3847/1538-4357/ae5dc1</a> <br /><br /><a href="https://www.scopus.com/pages/publications/105037975006?origin=resultslist" target="_blank" rel="noreferrer noopener">https://www.scopus.com/pages/publications/105037975006?origin=resultslist</a> Coverage The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant Devanand P.U., Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital, 263001, India, Department of Applied Physics/Physics, Mahatma Jyotiba Phule Rohilkhand University, Bareilly, 243006, India; Gupta A.C., Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital, 263001, India; Wiita P.J., Department of Physics, The College of New Jersey, 2000 Pennington Rd, Ewing, 08628-0718, NJ, United States; Jithesh V., Department of Physics and Electronics, Christ University, Hosur Main Rd, Bengaluru, 560029, India; Gupta A., Department of Applied Physics/Physics, Mahatma Jyotiba Phule Rohilkhand University, Bareilly, 243006, India Description An account of the resource We present an extensive X-ray spectral variability study of the TeV photon-emitting high-energy-peaked BL Lacertae object PG 1553+113, using the data from the EPIC-PN camera of XMM-Newton, which observed the source during its operational period from 2001 September to 2024 November. X-ray spectra in the energy range, 0.67.0 keV, were fitted with absorbed power-law (PL) and absorbed log-parabola (LP) models. We found with 99% confidence that 14 of them were fit well by LP models having parameters in the range ??2.132.80, and ??0.040.18, one spectrum flavors an LP model with ?&lt;0, while simple PL models with ??2.532.69 were sufficient to describe the X-ray spectra of the remaining 15. Of these 30 observations, 2 showed strong signatures of an additional inverse Compton component, while 1 showed weaker indications. On fitting joint Optical Monitor and EPIC-PN data with LP models, we found synchrotron peaks in the energy range of ?s?4.5948.61 eV. This indicates that the spectral evolution is probably caused by variations in particle acceleration or cooling conditions within the jet. 2026. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the https://creativecommons.org/licenses/by/4.0/. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Subject The topic of the resource BL Lacertae objects (158); Blazars (164); X-ray active galactic nuclei (2035) Publisher An entity responsible for making the resource available American Astronomical Society Relation A related resource ISSN: 0004637X; Language A language of the resource English Type The nature or genre of the resource Article Rights Information about rights held in and over the resource All Open Access; Gold Open Access; Green Open Access Format The file format, physical medium, or dimensions of the resource online