Results 1 to 10 of about 1,386,746 (158)
Two-injection Scenario for the Hard X-Ray Excess Observed in Mrk 421
The Astrophysical Journal, 2023 An interesting result that was recently reported for Mrk 421 is the detection of a significant excess at hard X-ray energies, which could provide useful information to investigate particle acceleration and emission mechanisms in the relativistic jet ...
Wen Hu, Da-Hai Yan, Qiang-Lin Hu
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The Astrophysical Journal Supplement Series, 2023 This paper presents the results of a detailed X-ray timing and spectral analysis of Mrk 501, which are based mainly on the Swift data obtained during 2021 February–2022 December. The source showed strongly enhanced X-ray activity, characterized by a long-
B. Kapanadze, A. Gurchumelia, M. Aller
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Gamma-ray Emission and Variability Processes in High-Energy-Peaked BL Lacertae Objects
Universe, 2023 BL Lac objects are active galactic nuclei notable for a beamed nonthermal radiation, which is generated in one of the relativistic jets forming a small angle to the observer’s line-of-sight.
Bidzina Kapanadze
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NuSTAR View of TeV Blazar Mrk 501
Galaxies, 2020 We report the results of flux and spectral variability studies of all seven Nuclear Spectroscopic Telescope Array (NuSTAR) observations of TeV γ-ray emitting blazar Markarian (or Mrk) 501.
Ashwani Pandey
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The Microvariable Activity of BL Lacertae
Galaxies, 2020 We report on seven nights of optical observation taken over a two-week period, and the resultant analysis of the intermediate-frequency peaked BL Lac object (IBL), BL Lac itself, at redshift z = 0.069. The microvariable behavior can be confirmed over the
Alberto C. Sadun +3 more
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A Small-scale Structure Model of a Jet Based on Observations of Microvariability
The Astrophysical Journal Supplement Series, 2023 We developed a multiregion radiation model for the evolution of flux and spectral index with time. In this model, each perturbation component in the jet produces an independent flare.
Jingran Xu +4 more
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X-ray Flux and Spectral Variability of Blazar H 2356-309
Galaxies, 2020 We present the results of timing and spectral analysis of the blazar H 2356-309 using XMM-Newton observations. This blazar is observed during 13 June 2005–24 December 2013 in total nine observations.
Kiran A. Wani, Haritma Gaur
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Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 Recent polarimetric surveys of extragalactic radio sources (ERS) at frequencies ν ≳ 1 GHz are reviewed. By exploiting all the most relevant data we study the frequency dependence of polarization properties of ERS between 1.4 and 86 GHz. For flat‐spectrum sources the median (mean) fractional polarization increases from 1.5% (2–2.5%) at 1.4 GHz to 2.5–3%
Marco Tucci +2 more
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Sub-Hour X-Ray Variability of High-Energy Peaked BL Lacertae Objects
Galaxies, 2018 The study of multi-wavelength flux variability in BL Lacertae objects is very important to discern unstable processes and emission mechanisms underlying their extreme observational features. While the innermost regions of these objects are not accessible
Bidzina Kapanadze
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Research of blazars at the Astronomical observatory of Belgrade [PDF]
Serbian Astronomical Journal, 2014 At the beginning of 2013, we have a team of scientists at the Astronomical Observatory of Belgrade, focusing on observations and research of blazars.
Vince O., Damljanović G.
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