English
Related papers

Related papers: Broadband Modelling of Orphan Gamma Ray Flares

200 papers

We extend our approach of modeling spectral energy distribution (SED) and lightcurves of blazars to include external Compton (EC) emission due to inverse Compton scattering of an external anisotropic target radiation field. We describe the…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Manasvita Joshi , Alan P. Marscher , Markus Boettcher

Blazars are a subclass of active galactic nuclei (AGN) that have a relativistic jet with a small viewing angle towards the observer. Recent results based on hadronic scenarios have motivated an ongoing discussion of how a blazar can produce…

High Energy Astrophysical Phenomena · Physics 2021-01-07 A. Rosales de León , A. M. Brown , P. M. Chadwick

It is surprising to find a fact for migration in the peak positions of synchrotron spectra energy distribution component during in the activity epochs of Mrk 421, accompanying with an orphan flaring at the X-ray and GeV-TeV $\gamma$-ray…

High Energy Astrophysical Phenomena · Physics 2021-02-10 Y. G. Zheng , C. Y. Yang , Shi-Ju Kang , J. M. Bai

We report on multiwavelength observations of the blazar PKS 0537-441 (z = 0.896) obtained from microwaves through gamma rays by SMA, REM, ATOM, Swift and Fermi during 2008 August-2010 April. Strong variability has been observed in gamma…

Using nearly simultaneous radio, near-infrared, optical, and ultraviolet data collected since 2009, we constructed 106 spectral energy distributions (SEDs) of the blazar OJ 287. These SEDs were well-fitted by a log-parabolic model. By…

We report the results of decade-long (2008-2018) $\gamma$-ray to 1 GHz radio monitoring of the blazar 3C 279, including GASP/WEBT, $\it{Fermi}$ and $\it{Swift}$ data, as well as polarimetric and spectroscopic data. The X-ray and…

The physics-determined broadband spectral energy distributions (SEDs) of blazars have been widely used to study the property during their flaring/outburst states, while the non-flaring state takes up most of their lifetime and the general…

High Energy Astrophysical Phenomena · Physics 2025-09-16 Hubing Xiao , Haitao Cao , Rui Xue , Zhihao Ouyang , Shaohua Zhang , Junping Chen , Zhijian Luo , Jianghe Yang , Junhui Fan

The 1ES 1959+650 is a high-peaked BL Lacertae object. On 4th of June, 2002, it exhibited a strong TeV flare without any low energy counterpart, providing for the first time an example of an orphan flare from a blazar. Observation of this…

High Energy Physics - Phenomenology · Physics 2015-06-16 Sarira Sahu , Andres Felipe Osorio Oliveros , Juan Carlos Sanabria

The active galactic nucleus 4C +28.07 is a flat spectrum radio quasar, one of the brightest at $\gamma$-ray energies. We study its multi-wavelength emission by analysing $\sim12.3$ years of \textit{Fermi-LAT} data in the $\gamma$-ray band…

High Energy Astrophysical Phenomena · Physics 2022-01-10 Davit Zargaryan , Jonathan Mackey , Thibault Barnouin , Felix Aharonian

Context: Being dominated by non-thermal emission from aligned relativistic jets, blazars allow us to elucidate the physics of extragalactic jets, and, ltimately, how the energy is extracted from the central black hole in radio-loud active…

The Yale/SMARTS optical-near-IR monitoring program has followed the variations in emission of the Fermi-LAT monitored blazars in the southern sky with closely spaced observations since 2008. We report the discovery of an optical-near-IR…

High Energy Astrophysical Phenomena · Physics 2013-03-11 Ritaban Chatterjee , G. Fossati , C. M. Urry , C. D. Bailyn , L. Maraschi , M. Buxton , E. W. Bonning , J. Isler , P. Coppi

High-redshift blazars are among the most powerful objects in the Universe. The spectral and temporal properties of thirty-three distant blazars ($z>2.5$) detected in the high energy $\gamma$-ray band are investigated by analyzing the {\it…

High Energy Astrophysical Phenomena · Physics 2020-08-25 N. Sahakyan , D. Israyelyan , G. Harutyunyan , M. Khachatryan , S. Gasparyan

Blazars are a subclass of active galactic nuclei (AGN) that emit non-thermal radiation through relativistic jets, characterized by rapid flux and polarization variability. High synchrotron-peaked blazars (HSPs) and extreme high…

High Energy Astrophysical Phenomena · Physics 2025-11-26 Adithiya Dinesh , Alberto Dominguez , V. Paliya , J. L. Contreras , S. Buson , M. Ajello

Blazar spectral models generally have numerous unconstrained parameters, leading to ambiguous values for physical properties like Doppler factor delta or fluid magnetic field B'. To help remedy this problem, a few modifications of the…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Charles D. Dermer , Matteo Cerruti , Benoit Lott , Catherine Boisson , Andreas Zech

Blazars are highly variable active galactic nuclei which emit radiation at all wavelengths from radio to gamma-rays. Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energies and it also varies…

There is a large variety in the models explaining blazar flares. Here, we study the flare profile induced by a moving and expanding blob with special emphasize on the gamma-gamma pair production. We first develop a simple semi-analytical…

High Energy Astrophysical Phenomena · Physics 2023-02-01 Michael Zacharias

We search through $\gamma$-ray data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope and find 24 blazars (or candidates) that have a single clear flare event in their 9.5 year long-term light curves.…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Gege Wang , Zhongxiang Wang , Liang Chen , Jianeng Zhou , Yi Xing

We investigate the origin of high-energy emission in blazars within the context of the leptohadronic one-zone model. We find that $\gamma$-ray emission can be attributed to synchrotron radiation either from protons or from secondary leptons…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Apostolos Mastichiadis , Maria Petropoulou , Stavros Dimitrakoudis

Blazars are promising sources of extragalactic high-energy astrophysical neutrinos, detected at energies $\gtrsim 10$ TeV by the IceCube neutrino observatory. Here, we report the first-ever broadband timing and spectral study of the…

High Energy Astrophysical Phenomena · Physics 2026-05-05 Suvas Chandra Chaudhary , Saikat Das , Raj Prince , Brian van Soelen

Multiwavelength observations of high energy flare in 1996 from 3C 279 seems to favour the so called mirror model between different inverse Compton scattering models proposed as a possible explanation of gamma-ray emission in blazars. We…

Astrophysics · Physics 2007-05-23 W. Bednarek