Abstract Details
| Name: Devanand P U Affiliation: Aryabhatta Research Instuite Of Observational Sciences, Nainital Conference ID: ASI2025_419 Title : X-Ray Spectral Variability of Thirteen TeV High Energy Peaked Blazars with XMM-Newton Authors and Co-Authors : P. U. Devanand 1,2, Alok C. Gupta 1, V. Jithesh 3, Paul J. Wiita 4, Archana Gupta 2 Abstract Type : Oral Abstract Category : High Energy Phenomena, Fundamental Physics and Astronomy Abstract : We present a comprehensive study of the X-ray spectral variability observed in 13 TeV photon emitting high energy peaked BL Lacs (HBLs): 1ES 0229+200, 1ES 0347-121, 1ES 0414+009, PKS 0548-322, 1ES 1028+511, 1ES 0647+250, 1ES 1101-232, 1H 1219+301, H 1426+428, Mrk 501, 1ES 1959+650, PKS 2005-489, and 1ES 2344+514. These data come from 54 XMM-Newton EPIC-PN pointed observations made during its operational period from June 2001 through July 2023. We performed spectral studies in the energy range 0.6--10 keV by fitting X-ray spectra of the pointed observations with power law (PL) and log parabolic (LP) models. We found at 99$\%$ confidence level that 31 of these X-ray spectra were best fitted with a range of LP models with local photon indices (at 1.0 keV), α ≃ 1.75–2.66, and convex curvature parameter β ≃ 0.02–0.25. PL models with photon index Γ ≃ 1.78–2.6 best described the spectra of fourteen-pointed observations. Nine PN spectra showed resulted in negative curvature parameter in fitting a LP model, and eight among them were significant (β≥2×βerr). We fitted broken power law (BPL) models to these eight X-ray spectra and found spectral hardening in the range of ΔΓ ≃ 0.06–0.54 for these observations. EPIC-MOS spectra were also studied for those eight observations to search for similar trends and we were able to find them in only two, one observation each of PKS 0548-322 and Mrk 501. This indicates the possibility of the co-existence of an inverse Compton component along with the dominant synchrotron component for these two observations. We also performed correlation studies between various log-parabolic spectral parameters and briefly discuss their possible implications. |