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Related papers: Revisiting the Blazar Main Sequence

200 papers

We study the BL Lac objects detected in the one year all sky survey of the Fermi satellite, with a energy spectral slope alpha_gamma in the [0.1-100 GeV] band greater than 1.2. In the alpha_gamma vs gamma-ray luminosity plane, these BL Lacs…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 G. Ghisellini , F. Tavecchio , L. Foschini , G. Ghirlanda

Blazars, a subclass of radio-loud active galactic nuclei with relativistic jets aligned close to our line of sight, emit highly variable non-thermal radiation across the electromagnetic spectrum. The physical origin of their emission and…

High Energy Astrophysical Phenomena · Physics 2026-01-14 Stella Boula , Apostolos Mastichiadis , Demosthenes Kazanas

Blazars' non-thermal emission shows rapid variability across all wavelengths, so spectral energy distributions (SEDs) built from quasi-simultaneous data are crucial for revealing the jets physical properties. In this work, we construct…

High Energy Astrophysical Phenomena · Physics 2026-05-22 Yi Zhong , Zhujian Wan , Rui Xue , Hubing Xiao , Dingrong Xiong , Ze-Rui Wang

We re-examine the differences observed in the pc-scale magnetic field geometry of high and low optical polarization Quasars (HPQs, LPRQs) using the MOJAVE sample. We find that, as previously reported, HPQ jets exhibit predominantly…

Astrophysics · Physics 2009-06-23 P. Kharb , M. L. Lister , P. Shastri

We examine the fundamental plane of 91 Blazars which include FSRQs and BL Lacs with known X-ray luminosity ($L_{R}$), radio luminosity ($L_X$), and black hole mass measurements ($M$) to reflect the relationship between jet and accretion for…

High Energy Astrophysical Phenomena · Physics 2024-03-15 Xu Zhang , Dingrong Xiong , Quangui Gao , Guiqin Yang , Fangwu Lu , Weiwei Na , Longhua Qin

With high-sensitivity kiloparsec-scale radio polarimetry, we can examine the jet-medium interactions and get a better understanding of the blazar divide in radio-loud (RL) AGN. We are analyzing the radio polarimetric observations with the…

Astrophysics of Galaxies · Physics 2023-04-25 Janhavi Baghel , P. Kharb , Silpa S. , Luis C. Ho , C. M. Harrison

The characteristic properties of blazars (rapid variability, strong polarization, high brightness) are widely attributed to a powerful relativistic jet oriented close to our line of sight. Despite the spectral energy distributions (SEDs)…

Astrophysics of Galaxies · Physics 2015-05-13 E. J. D. Jolley , Z. Kuncic , G. V. Bicknell , S. Wagner

Blazars are conventionally classified into BL Lac objects and flat-spectrum radio quasars (FSRQs), commonly associated with radiatively inefficient and efficient accretion onto supermassive black holes, respectively. Increasing evidence,…

High Energy Astrophysical Phenomena · Physics 2026-05-18 Javaid Tantry , Naseer Iqbal

In our review of the blazar phenomenon, we discuss blazar models, with a focus on the following issues: sub-parsec jets and their environment; energy dissipation and particle acceleration; and radiative processes.

Astrophysics · Physics 2009-11-06 M. Sikora , G. Madejski

A hyperaccreting stellar-mass black hole has been proposed as the candidate central engine of gamma-ray bursts (GRBs). The rich observations of GRBs by \textit{Fermi} and \textit{Swift} make it possible to constrain the central engine model…

High Energy Astrophysical Phenomena · Physics 2017-11-08 Wei-Hua Lei , Bing Zhang , Xue-Feng Wu , En-Wei Liang

We explore the viability of the unification of BL Lacs and FR I radio galaxies by comparing the core emission of radio galaxies with those of BL Lacs of similar extended radio power, taking advantage of the newly measured optical nuclear…

Astrophysics · Physics 2007-05-23 Marco Chiaberge , Annalisa Celotti , Alessandro Capetti , Gabriele Ghisellini

We present the first observations at medium-hard X-rays with ASCA in 1998 August--November of four Flat Spectrum Radio Quasars (FSRQs), characterized by unusually steep soft X-ray spectra (photon index, \Gamma_{0.2-2.4 keV} \sim 2-2.5), as…

Astrophysics · Physics 2009-10-31 Rita M. Sambruna , Lester L. Chou , C. Megan Urry

The dissipation of energy flux in blazar jets plays a key role in the acceleration of relativistic particles. Two possibilities are commonly considered for the dissipation processes, magnetic reconnection -- possibly triggered by…

High Energy Astrophysical Phenomena · Physics 2018-06-13 F. Tavecchio , M. Landoni , L. Sironi , P. Coppi

The particle acceleration of blazar jets is crucial to high-energy astrophysics, yet the acceleration mechanism division in blazar subclasses and the underlying nature of these mechanisms remain elusive. In this work, we utilized the…

High Energy Astrophysical Phenomena · Physics 2024-04-09 Hubing Xiao , Wenxin Yang , Yutao Zhang , Shaohua Zhang , Junhui Fan , Liping Fu , Jianghe Yang

The phenomenology of gamma-ray bright blazars can be accounted for by a sequence in the source power and intensity of the diffuse radiation field surrounding the relativistic jet. Correspondingly, the equilibrium particle distribution peaks…

Astrophysics · Physics 2009-10-30 G. Ghisellini , A. Celotti , G. Fossati , L. Maraschi , A. Comastri

In this paper we investigate the properties of a sample of six BL Lacs by fitting their spectra using our inhomogeneous jet model with an accelerating, magnetically dominated, parabolic base, which transitions to a slowly decelerating…

High Energy Astrophysical Phenomena · Physics 2015-06-17 William J. Potter , Garret Cotter

Our knowledge of the blazar surface densities and luminosity functions, which are fundamental parameters, relies still on samples at relatively high flux limits. As a result, our understanding of this rare class of active galactic nuclei is…

Astrophysics · Physics 2011-02-11 P. Padovani , P. Giommi , H. Landt , E. S. Perlman

Blazars are usually classified following their synchrotron peak frequency ($\nu F(\nu)$ scale) as high, intermediate, low frequency peaked BL Lacs (HBLs, IBLs, LBLs), and flat spectrum radio quasars (FSRQs), or, according to their radio…

High Energy Astrophysical Phenomena · Physics 2016-07-06 Olivier Hervet , Catherine Boisson , Hélène Sol

We consider internal shocks as the main dissipation mechanism responsible for the emission in blazars and show that it can satisfactorily account for the properties of all blazars. In particular, we extend previous work (Spada et al. 2001)…

Astrophysics · Physics 2009-11-10 Dafne Guetta , Gabriele Ghisellini , Davide Lazzati , Annalisa Celotti

A small subset of optically selected radio-quiet quasars showing weak or no emission lines may turn out to be the elusive radio-quiet BL Lac objects, or simply be radio-quiet QSOs with a still-forming/shielded broad line region (BLR). High…

High Energy Astrophysical Phenomena · Physics 2018-07-25 Parveen Kumar , H. Chand , R. Srianand , C. S. Stalin , P. Petitjean , Gopal-Krishna