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The high frequency component in blazars is thought to be due to inverse Compton scattered radiation. Recent observations by Fermi-LAT are used to evaluate the details of the scattering process. A comparison is made between the usually…

High Energy Astrophysical Phenomena · Physics 2015-05-19 C. -I. Björnsson

In a previous paper, we proposed a new method to select low-power BL Lacs (LPBLs) based on mid-infrared emission and flux contrast through the Ca II spectral break; that study led to the selection of a complete sample formed by 34 LPBLs…

Astrophysics of Galaxies · Physics 2016-02-17 Claudia M. Raiteri , Alessandro Capetti

The origin and evolution of spectral curvature in blazar spectral energy distribution (SED) is still unclear. Since the observed SED curvature is related to an intrinsic curvature in emitting electron energy distribution (EED), we study…

High Energy Astrophysical Phenomena · Physics 2020-07-29 Muhammad S. Anjum , Liang Chen , Minfeng Gu

We present a comprehensive temporal and spectral analysis of a few blazars using multi-wavelength observations. Rapid flux variations are quantified via the doubling/halving timescale method, revealing the shortest variability timescales of…

High Energy Astrophysical Phenomena · Physics 2025-06-17 Ajay Sharma , Aishwarya Sarath , Sakshi Chaudhary , Debanjan Bose

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

In this work we investigate the nature of multi-wavelength variability of blazars from a purely numerical approach. We use a time-dependent one-zone leptonic blazar emission model to simulate multi-wavelength variability by introducing…

High Energy Astrophysical Phenomena · Physics 2022-02-09 Hannes Thiersen , Michael Zacharias , Markus Böttcher

In this paper, we use the quasi-simultaneous spectra of Fermi bright blazars and Fermi detected narrow line Seyfert 1 (NLS1) to study the blazar sequence and inverse Compton (IC) models. I. The synchrotron peak luminosities (L_{s})…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Liang Chen , J. M. Bai

We revisit the blazar sequence exploiting the complete, flux limited sample of blazars with known redshift detected by the Fermi satellite after 4 years of operations (the 3LAC sample). We divide the sources into gamma-ray luminosity bins,…

High Energy Astrophysical Phenomena · Physics 2017-05-31 G. Ghisellini , C. Righi , L. Costamante , F. Tavecchio

The broadband spectral energy distribution(SED) of blazars is generally interpreted as radiation arising from synchrotron and inverse Compton mechanisms.Traditionally, the underlying source parameters responsible for these emission…

High Energy Astrophysical Phenomena · Physics 2018-04-04 S. Sahayanathan , A. Sinha , R. Misra

We present simultaneous optical and X-ray data from Swift for a sample of FSRQs selected from the EMSS survey. We present also a complete analysis of Swift and INTEGRAL data on 4 blazars recently discussed as possibly challenging the trends…

Astrophysics · Physics 2009-11-13 L. Maraschi , L. Foschini , G. Ghisellini , F. Tavecchio , R. M. Sambruna

In a companion paper we presented a statistical model for the blazar population, consisting of distributions for the unbeamed radio luminosity function and the Lorentz factor distribution of each of the BL Lac and Flat Spectrum Radio Quasar…

High Energy Astrophysical Phenomena · Physics 2015-10-21 I. Liodakis , V. Pavlidou

We have studied the quasi-simultaneous Spectral Energy Distributions (SED) of 48 LBAS blazars, detected within the three months of the LAT Bright AGN Sample (LBAS) data taking period, combining Fermi and Swift data with radio NIR-Optical…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 A. Tramacere , E. Cavazzuti , P. Giommi , N. Mazziotta , C. Monte

We collect data from the radio to the gamma-ray range for three complete samples of blazars: the Slew Survey and the 1Jy samples of BL Lacs and the 2Jy sample of Flat Spectrum Radio-Loud Quasars (FSRQs). The fraction of objects detected in…

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

In this review, recent progress in theoretical models for the broadband (radio through gamma-ray) emission from blazars are summarized. The salient features of both leptonic and hadronic models are reviewed. I present sample modeling…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-03 Markus Boettcher

Average Spectral Energy Distributions (SED) for different subgroups of blazars are derived from available homogeneous (but small) data sets, including the gamma-ray band. Comparing Flat Spectrum Radio Quasars (FSRQ) with BL Lacs extracted…

Astrophysics · Physics 2007-05-23 Laura Maraschi , Giovanni Fossati

Single-zone synchrotron self-Compton and external Compton models are widely used to explain broad-band Spectral Energy Distributions (SEDs) of blazars from infrared to gamma-rays. These models bear obvious similarities to the homogeneous…

Blazars are among the most powerful extragalactic objects, as a sub-class of active galactic nuclei. They launch relativistic jets and their emitted radiation shows strong variability across the entire electro-magnetic spectrum. The…

High Energy Astrophysical Phenomena · Physics 2015-08-12 C. M. Fromm , L. Fuhrmann , M. Perucho

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

(Abridged) We have conducted a detailed investigation of the broad-band spectral properties of the \gamma-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated Fermi gamma-ray spectra with…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 A. A. Abdo , M. Ackermann , M. Ajello , M. Axelsson , L. Baldini , J. Ballet , G. Barbiellini , D. Bastieri , B. M. Baughman , K. Bechtol , R. Bellazzini , B. Berenji , R. D. Blandford , E. D. Bloom , E. Bonamente , A. Borgland , J. Bregeon , A. Brez , M. Brigida , P. Bruel , T. H. Burnett , S. Buson , G. A. Caliandro , R. A. Cameron , P. A. Caraveo , J. M. Casandjian , E. Cavazzuti , C. Cecchi , O. Celik , E. Charles , S. Chaty , A. Chekhtman , J. Chiang , S. Ciprini , R. Claus , J. Cohen-Tanugi , S. Colafrancesco , L. R. Cominsky , J. Conrad , L. Costamante , S. Cutini , C. D. Dermer , A. de Angelis , F. de Palma , S. W. Digel , E. do Couto e Silva , P. S. Drell , R. Dubois , D. Dumora , C. Farnier , C. Favuzzi , S. J. Fegan , W. B. Focke , P. Fortin , M. Frailis , L. Fuhrmann , Y. Fukazawa , S. Funk , P. Fusco , F. Gargano , D. Gasparrini , N. Gehrels , S. Germani , B. Giebels , N. Giglietto , P. Giommi , F. Giordano , T. Glanzman , G. Godfrey , I. A. Grenier , J. E. Grove , L. Guillemot , S. Guiriec , D. Hadasch , Y. Hanabata , A. K. Harding , M. Hayashida , E. Hays , S. E. Healey , D. Horan , R. E. Hughes , R. Itoh , M. S. Jackson , G. Johannesson , A. S. Johnson , W. N. Johnson , M. Kadler , T. Kamae , H. Katagiri , J. Kataoka , N. Kawai , M. Kerr , J. Knodlseder , M. L. Kocian , M. Kuss , J. Lande , L. Latronico , F. Longo , F. Loparco , B. Lott , M. N. Lovellette , P. Lubrano , G. M. Madejski , A. Makeev , W. Max-Moerbeck , M. N. Mazziotta , W. McConville , J. E. McEnery , C. Meurer , P. F. Michelson

We revisit the so called "blazar sequence", which connects the observed bolometric luminosity to the shape of the spectral energy distribution (SED) of blazars. We propose that the power of the jet and the SED of its emission are linked to…

Astrophysics · Physics 2009-11-13 G. Ghisellini , F. Tavecchio