English
Related papers

Related papers: Models of variability in blazar jets

200 papers

Jet models for the high-energy emission of Galactic X-ray binary sources have regained significant interest with detailed spectral and timing studies of the X-ray emission from microquasars, the recent detection by the HESS collaboration of…

Astrophysics · Physics 2009-11-11 Swati Gupta , Markus Boettcher , Charles D. Dermer

The long-term variability study over a range of black hole (BH) mass systems from the microquasars of stellar-mass black holes to the Active Galactic Nuclei (AGNs) of supermassive black holes, in $\gamma$-rays offers new insights into the…

High Energy Astrophysical Phenomena · Physics 2024-10-10 Ajay Sharma , Raj Prince , Debanjan Bose

One of the most important questions in blazar physics is the origin of broadband emission and fast-flux variation. In this work, we studied the broadband temporal and spectral properties of a TeV blazar 1ES 1727+502 and explore the one-zone…

High Energy Astrophysical Phenomena · Physics 2022-07-20 Raj Prince , Rukaiya Khatoon , Pratik Majumdar , Bożena Czerny , Nayantara Gupta

In the first of a series of papers investigating emission from blazar jets from radio to high-energy {\gamma}-rays, we revisit the class of models where the jet has a uniform conical ballistic structure. We argue that by using simple…

High Energy Astrophysical Phenomena · Physics 2012-12-13 William J. Potter , Garret Cotter

The relationship between observed variability time and emission region geometry is explored for the case of emission by relativistic jets. The approximate formula for the jet-frame size of the emission region, $R'=Dc\Delta t_{\rm obs}$ is…

Astrophysics · Physics 2009-11-07 R. J. Protheroe

We summarize broadband observations of the TeV-emitting blazar 1ES 1959+650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift UVOT, X-ray observations by the Swift X-ray…

Blazars, a highly variable Active Galactic Nuclei (AGNs) subclass, provide a unique opportunity to explore the physical processes within their relativistic jets and emission regions. In this study, we investigate the multiwavelength…

High Energy Astrophysical Phenomena · Physics 2025-11-24 Jonhatan U. Guerrero-González , Vahram Chavushyan , Víctor M. Patiño-Álvarez

The observed log-normal flux distributions in the high energy emission from blazars have been interpreted as being due to variability stemming from non-linear multiplicative processes generated dynamically from the accretion disc. On the…

High Energy Astrophysical Phenomena · Physics 2018-07-26 Atreyee Sinha , Rukaiya Khatoon , Ranjeev Misra , Sunder Sahayanathan , Soma Mandal , Rupjyoti Gogoi , Nilay Bhatt

X-ray observations are essential for understanding the multimessenger emission mechanisms of active galactic nuclei (AGN). Blazars, a subset of AGN whose X-ray emission predominantly originates from relativistic jets, have been proposed as…

High Energy Astrophysical Phenomena · Physics 2025-07-18 Jose Maria Sanchez Zaballa , Sara Buson , Stefano Marchesi , Francesco Tombesi , Thomas Dauser , Joern Wilms , Alessandra Azzollini

We analyze the variability of the parsec-scale jet directions in active galactic nuclei (AGNs). Our analysis involves 317 AGNs at frequencies ranging from 2 to 43 GHz, and is made possible by developing an automatic inner jet direction…

High Energy Astrophysical Phenomena · Physics 2025-02-11 Ivan Kostrichkin , Alexander Plavin , Alexander Pushkarev , Marina Butuzova

We analyse the ultraviolet variability time scales in a sample of 15 Type 1 Active Galactic Nuclei (AGN) observed by IUE. Using a structure function analysis, we demonstrate the existence in most objects of a maximum variability time scale…

Astrophysics · Physics 2009-11-11 P. Favre , T. J. -L. Courvoisier , S. Paltani

Variability is a general property of accretion discs and their associated jets. We introduce a semi-analytic model for particle acceleration and radio jet/lobe evolution and explore the effect of Myr timescale jet variability on the…

High Energy Astrophysical Phenomena · Physics 2021-03-24 James H. Matthews , Andrew M. Taylor

Variability studies hold information on otherwise unresolvable regions in Active Galactic Nuclei (AGN). Population studies of large samples likewise have been very productive for our understanding of AGN. These two themes are coming…

High Energy Astrophysical Phenomena · Physics 2016-05-31 Andy Lawrence

With the anticipated launch of GLAST, the existing X-ray telescopes, and the enhanced capabilities of the new generation of TeV telescopes, developing tools for modeling the variability of high energy sources such as blazars is becoming a…

A large fraction of the AGNs detected by EGRET exhibit strong variability in many wavebands- from radio to the highest energy gamma-rays observed. The origin of the transient emission in blazars is presumably associated with relativistic…

Astrophysics · Physics 2007-05-23 Amir Levinson

Active Galactic Nuclei (AGNs) are characterized by emission of radiation over more than 10 orders of magnitude in frequency. Therefore, the execution of extensive surveys of the sky, with different types of detectors, is providing the…

PKS 1510-089 is one of the most variable blazars. Very high energy gamma ray emission from this source was observed by H.E.S.S. during March-April 2009 and by MAGIC from February 3 to April 3, 2012 quasi-simultaneously with multi-wavelength…

High Energy Astrophysical Phenomena · Physics 2017-02-15 Partha Pratim Basumallick , Nayantara Gupta

Here we report our recent study on the spectral energy distribution (SED) of the high frequency BL Lac object Mrk 421 in different luminosity states. We used a full-fledged chi2-minimization procedure instead of more commonly used "eyeball"…

High Energy Astrophysical Phenomena · Physics 2011-11-02 Nijil Mankuzhiyil , Stefano Ansoldi , Massimo Persic , Fabrizio Tavechhio

X-ray emission from large scale extragalactic jets is likely to be due to inverse Compton scattering of relativistic particles off seed photons of both the cosmic microwave background field and the blazar nucleus. The first process…

Astrophysics · Physics 2009-10-31 A. Celotti , G. Ghisellini , M. Chiaberge

We describe a geometric model for synchrotron and synchrotron self-Compton (SSC) radiation from blazar jets, involving multiple emission zones with turbulent magnetic fields and fully self-consistent seed photon mixing for SSC. Including…

High Energy Astrophysical Phenomena · Physics 2020-01-08 A. L. Peirson , R. W. Romani