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Related papers: Unifying MeV-blazars with GeV-blazars

200 papers

The GeV-range spectra of blazars are shaped not only by non-thermal emission processes internal to the relativistic jet but also by external pair-production absorption on the thermal emission of the accretion disc and the broad-line region…

High Energy Astrophysical Phenomena · Physics 2016-09-21 Pavel Abolmasov , Juri Poutanen

The synergy between the Fermi-LAT and ground-based Cherenkov telescope arrays gives us the opportunity for the first time to characterize the high-energy emission from blazars over 5 decades in energy, from 100 MeV to 10 TeV. In this study,…

High Energy Astrophysical Phenomena · Physics 2015-06-12 G. D. Senturk , M. Errando , M. Boettcher , R. Mukherjee

We compiled the radio, optical, and X-ray data of blazars from the Sloan Digital Sky Survey (SDSS) database, and presented the distribution of luminosities and broad band spectral indices. The distribution of luminosities shows that the…

High Energy Astrophysical Phenomena · Physics 2015-03-20 Huaizhen Li , Luoen Chen , Yunguo Jiang , Tingfeng Yi

Many quasi-simultaneous optical observations of 17 blazars are obtained from previous papers published over the last 19 years in order to investigate the spectral slope variability and understand the radiation mechanism of blazars. The…

Astrophysics · Physics 2019-09-04 Shao Ming Hu , G. Zhao , H. Y. Guo , X. Zhang , Y. G. Zheng

The \gamma-ray loud blazars (flat spectrum radio quasars--FSRQs and BL Lacertae objects-BLs) are very bright in the \gamma-ray bands, which is perhaps associated with a beaming effect. Therefore, one can expect that the \gamma-ray…

High Energy Astrophysical Phenomena · Physics 2015-06-11 J. H. Fan , J. H. Yang , J. Y. Zhang , T. X. Hua , Y. Liu , Y. P. Qin , Y. Huang

The knowledge of the physical conditions occurring in the relativistic jet of radio-loud active galactic nuclei (AGNs) is important to understand the mechanisms at the basis of their multiband emission. From parsec-scale radio observations…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-29 M. Orienti , G. Giovannini , D. Dallacasa , M. Giroletti , T. Venturi , F. D'Ammando , S. Vercellone , M. Tavani

Observations of very-high-energy (VHE, E > 250 GeV) gamma-ray emission from several blazars at z > 0.1 have placed stringent constraints on the elusive spectrum and intensity of the intergalactic infrared background radiation (IIBR).…

Astrophysics · Physics 2009-11-13 Markus Boettcher , Charles D. Dermer , Justin D. Finke

Violent multi-wavelength variabilities are observed in gamma-ray-selected blazars. We present an analysis of long-term light curves for eight bright blazars to explore the co-variation pattern in the gamma-ray and radio bands. We extract…

High Energy Astrophysical Phenomena · Physics 2020-05-27 Hai-Ming Zhang , Zhen-Jie Wang , Jin Zhang , Ting-Feng Yi , Liang Chen , Rui-Jing Lu , En-Wei Liang

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

Blazars are known for their variability on a wide range of timescales at all wavelengths. Most studies of TeV gamma-ray blazars focus on short timescales, especially during flares. With a decade of observations from the Fermi-LAT and…

Knowing the site of gamma-ray emission in AGN jets will do much for our understanding of the physics of the source. In particular, if the emission region is close to the black hole then absorption of gamma-rays with photons from the…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Jonathan Harris , Michael K. Daniel , Paula M. Chadwick

Fast radio bursts (FRBs) are bright milliseconds-duration radio bursts from cosmological distances. Despite intense observational and theoretical studies, their physical origin is still mysterious. One major obstacle is the lack of…

High Energy Astrophysical Phenomena · Physics 2024-11-12 Yi Xing , Wenfei Yu , Zhen Yan , Xian Zhang , Bing Zhang

We report on optical spectroscopy of 165 Flat Spectrum Radio Quasars (FSRQs) in the Fermi 1LAC sample, which have helped allow a nearly complete study of this population. Fermi FSRQ show significant evidence for non-thermal emission even in…

The MeV spectral peak of gamma-ray bursts (GRBs) is best explained as photospheric emission from a dissipative relativistic jet. The observed non-blackbody spectrum shows that sub-photospheric dissipation involves both thermal plasma…

High Energy Astrophysical Phenomena · Physics 2016-11-07 Christoffer Lundman , Indrek Vurm , Andrei M. Beloborodov

We have recently proposed a new scenario where blazars are classified as flat-spectrum radio quasars or BL Lacs according to the prescriptions of unified schemes, and to a varying combination of Doppler boosted radiation from the jet,…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-11 Paolo Giommi , Paolo Padovani

The origin of the gamma-ray emission of the blazar Mrk 421 is still a matter of debate. We used 5.5 years of unbiased observing campaign data, obtained using the FACT telescope and the Fermi LAT detector at TeV and GeV energies, the longest…

Based on the classical unification, blazars, namely BL Lacertae objects (BL Lacs) and flat-spectrum radio quasars (FSRQs), are believed to correspond with radio galaxies when observed at small jet viewing angles. In this paper, we aim to…

High Energy Astrophysical Phenomena · Physics 2026-04-01 Xu-Hong Ye , Ranieri D. Baldi , Wen-Xin Yang , Jing-Tian Zhu , Denis Bastieri , Rumen S. Bachev , Anton A. Strigachev , Jun-Hui Fan

The Fermi Large Area Telescope (LAT) revealed that blazars, representing the most extreme radio-loud active galactic nuclei (AGN) population, dominate the census of the gamma-ray sky, and a significant correlation was found between radio…

High Energy Astrophysical Phenomena · Physics 2017-10-30 R. Lico , M. Giroletti , M. Orienti , L. Costamante , V. Pavlidou , F. D'Ammando , F. Tavecchio

We investigate the spectral properties of the brightest gamma-ray flares of blazars detected by the Fermi Large Area Telescope. We search for the presence of spectral breaks and measure the spectral curvature on typical time scales of a few…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Susanna Kohler , Krzysztof Nalewajko

Blazars optical emission is generally dominated by relativistic jets, although the host galaxy, accretion disk and broad line region (BLR) may also contribute significantly. Disentangling their contributions has been challenging for years…

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