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Related papers: A simplified view of blazars: the gamma-ray case

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The expected level of gamma-gamma absorption in the Broad Line Region (BLR) radiation field of gamma-ray loud Flat Spectrum Radio Quasars (FSRQs)is evaluated as a function of the location of the gamma-ray emission region. This is done…

High Energy Astrophysical Phenomena · Physics 2016-04-27 Markus Boettcher , Paul Els

We report the results of our exploratory program carried out with the Southern Astrophysical Research (SOAR) telescope aimed at associating counterparts and establishing the nature of the Fermi Unidentified gamma-ray Sources (UGS). We…

High Energy Astrophysical Phenomena · Physics 2015-06-24 M. Landoni , F. Massaro , A. Paggi , R. D'Abrusco , D. Milisavljevic , N. Masetti , Howard. A. Smith , G. Tosti , L. Chomiuk , J. Strader , C. C. Cheung

We report multi-wavelength (IR-O, UV, X-ray, gamma-ray) data of the flat spectrum radio quasar (FSRQ) PKS B1424-418 (z=1.52) gathered during an active phase in 2013 April . As for a few other cases of FSRQs reported in literature, the…

High Energy Astrophysical Phenomena · Physics 2015-06-16 F. Tavecchio , L. Pacciani , I. Donnarumma , A. Stamerra , J. Isler , E. MacPherson , C. M. Urry

The blazar zone in quasars is commonly assumed to be located inside the broad-line region at some hundreds of Schwartzschild radii from the central black hole. Now, the simultaneous Fermi/LAT and MAGIC observations of a strong flare in the…

High Energy Astrophysical Phenomena · Physics 2019-08-15 A. Stamerra , J. Becerra , G. Bonnoli , L. Maraschi , F. Tavecchio , D. Mazin , K. Saito , Y. Tanaka , D. Wood

We present a new X-ray luminosity function of flat-spectrum radio quasars (FSRQs) utilizing the latest {\it Swift}/BAT 105-month X-ray source catalog. Contrary to previous studies of FSRQs in the X-ray band, using the luminosity-dependent…

High Energy Astrophysical Phenomena · Physics 2020-07-01 Koyo Toda , Yasushi Fukazawa , Yoshiyuki Inoue

The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long Baseline Array (VLBA). In total, 232 sources were observed with…

Blazars are the brightest and most abundant persistent sources in the extragalactic gamma-ray sky. Due to their significance, they are often observed across various energy bands to explore potential correlations between emissions at…

High Energy Astrophysical Phenomena · Physics 2024-01-22 P. Giommi , N. Sahakyan , D. Israyelyan , M. Manvelyan

We present results from a deep VERITAS exposure of the distant (z=0.89) flat-spectrum radio quasar (FSRQ) 4C +55.17. The high flux, hard index and steady emission found by Fermi LAT observations make this blazar a promising very-high-energy…

High Energy Astrophysical Phenomena · Physics 2013-03-06 Amy Furniss , William McConville

Blazars radiate from relativistic jets launched by a supermassive black hole along our line of sight; the subclass of FSRQs exhibits broad emission lines, a telltale sign of a gas-rich environment and high accretion rate, contrary to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Alessandro Paggi , Alfonso Cavaliere , Valerio Vittorini , Filippo D'Ammando , Marco Tavani

We analyse a group of radio sources, a subset of the 200 mJy sample, all of which have core-jet radio structures measured with VLBI and have flat spectra stretching from the radio to the millimetre/sub-millimetre band. Thus the objects have…

Astrophysics · Physics 2009-11-10 S. Anton , I. W. A. Browne

Blazars are a small fraction of all extragalactic sources but, unlike other objects, they are strong emitters across the entire electromagnetic spectrum. Recent data in the microwave region of the electromagnetic spectrum have become…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-24 D. Gasparrini , E. Cavazzuti , P. Giommi , C. Pittori , S. Colafrancesco , Fermi-LAT collaboration

We propose a sequence (the Blazar main sequence, BMS) that links the two main components of the Blazar class, namely, the Flat Spectrum Radio Quasars and the BL Lacertae objects, and yields all their distinctive features in a correlated…

Astrophysics · Physics 2009-11-06 A. Cavaliere , V. D'Elia

Blazars are radio-loud Active Galactic Nuclei (AGN) whose jets have a very small angle to our line of sight. Observationally, the radio emission are mostly compact or a compact-core with a 1-sided jet. With 2.5$^{\prime\prime}$ resolution…

Blazars can be divided into two subtypes, flat spectrum radio quasars (FSRQs) and BL Lac objects, which have been distinguished phenomenologically by the strength of their optical emission lines, while their physical nature and relationship…

High Energy Astrophysical Phenomena · Physics 2020-07-22 Makoto Uemura , Taisei Abe , Yurika Yamada , Shiro Ikeda

An equivalent width (EW) based classification may cause the erroneous judgement to the flat spectrum radio quasars (FSRQs) and BL Lacerate objects (BL Lac) due to the diluting the line features by dramatic variations in the jet continuum…

High Energy Astrophysical Phenomena · Physics 2023-08-14 Shi-Ju Kang , Yong-Gang Zheng , Qingwen Wu

The flat spectrum radio quasar (FSRQ) PKS 2123-463 was associated in the First Fermi-LAT source catalog with the gamma-ray source 1FGL J2126.1-4603, but when considering the full first two years of Fermi observations, no gamma-ray source at…

High Energy Astrophysical Phenomena · Physics 2015-06-11 F. D'Ammando , A. Rau , P. Schady , J. Finke , M. Orienti , J. Greiner , D. A. Kann , R. Ojha , A. R. Foley , J. Stevens , J. M. Blanchard , P. G. Edwards , M. Kadler , J. E. J. Lovell

The $\gamma-$ray emission from flat-spectrum radio quasars (FSRQs) is thought to be dominated by the inverse Compton scattering of the external sources of photon fields, e.g., accretion disk, broad-line region (BLR), and torus. FSRQs show…

High Energy Astrophysical Phenomena · Physics 2022-11-16 Savithri H. Ezhikode , Amit Shukla , Gulab C. Dewangan , Pramod K. Pawar , Sushmita Agarwal , Blesson Mathew , Akhil Krishna R

This paper presents XMM-Newton and Chandra X-ray spectroscopy of ten flat-spectrum radio quasars (FSRQ) which are candidates to have an X-ray spectrum dominated by jet synchrotron emission. In all these FSRQ, which are less strongly…

Astrophysics · Physics 2010-11-11 Hermine Landt , Paolo Padovani , Paolo Giommi , Matteo Perri , Chi C. Cheung

A large sample of blazar from the Candidate Gamma Ray Blazar Survey (CGRaBS) has been observed with the Owens Valley Radio Observatory (OVRO) 40-Meter Telescope at 15GHz. Using these quasi-simultaneous observations, we study the connection…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-15 Walter Max-Moerbeck

Context. The gamma-ray emitting source WISE J141046.00+740511.2 has been associated with a Fermi-LAT detection by crossmatching with Swift/XRT data. It has shown all the canonical observational characteristics of a BL Lac source, including…