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Related papers: On the gamma-ray emission from 3C 120

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Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2 sq-mt sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Luca Latronico

The flux of gamma rays with energies >100MeV is dominated by diffuse emission from CRs illuminating the ISM of our Galaxy through the processes of Bremsstrahlung, pion production and decay, and inverse-Compton scattering. The study of this…

High Energy Astrophysical Phenomena · Physics 2017-02-22 LAT collaboration

We present the light curves and spectral data of two exceptionally luminous gamma-ray outburts observed by the Large Area Telescope (LAT) experiment on board Fermi Gamma-ray Space Telescope from 3C 273 in September 2009. During these…

High Energy Astrophysical Phenomena · Physics 2015-05-20 A. A. Abdo et al.

We present a \gamma-ray photon flux and spectral variability study of the flat-spectrum radio quasar 3C 273 over a rapid flaring activity period between September 2009 to April 2010. Five major flares are observed in the source during this…

High Energy Astrophysical Phenomena · Physics 2015-06-16 B. Rani , B. Lott , T. P. Krichbaum , L. Fuhrmann , J. A. Zensus

We report Fermi/LAT observations and broad-band spectral modeling of the radio-loud active galaxy 4C +55.17 (z=0.896), formally classified as a flat-spectrum radio quasar. Using 19 months of all-sky survey Fermi/LAT data, we detect a…

We present the results of our analysis of cosmic-ray electrons using about 8 million electron candidates detected in the first 12 months on-orbit by the Fermi Large Area Telescope. This work extends our previously-published cosmic-ray…

High Energy Astrophysical Phenomena · Physics 2012-08-27 Fermi LAT collaboration

The high energy spectral shape of 3C 273 is usually understood in terms of Inverse-Compton emission in a relativistic leptonic jet. This model predicts variability patterns and delays which could be tested if simultaneous observations are…

High Energy Astrophysical Phenomena · Physics 2013-04-29 Valentino Esposito , Roland Walter , Pierre Jean , Andrea Tramacere

Using 3.7 years of \Fermi-LAT data, we examine the diffuse 80-200 GeV emission in the inner Galaxy and find a resolved gamma-ray feature at $\sim 110-140$ GeV. We model the spatial distribution of this emission with a $\sim3\degree$ FWHM…

High Energy Astrophysical Phenomena · Physics 2012-06-15 Meng Su , Douglas P. Finkbeiner

We investigate the physical mechanisms of high-energy gamma-ray emission from the TeV-emitting misaligned active galactic nucleus IC 310. Eight years of data from the Fermi Large Area Telescope (Fermi-LAT) between 100 MeV and 500 GeV are…

High Energy Astrophysical Phenomena · Physics 2019-03-20 Jamie Graham , Anthony Brown , Paula Chadwick

GRB 131231A was detected by the Large Area Telescope onboard Fermi Space Gamma-ray Telescope. The high energy gamma-ray ($> 100$ MeV) afterglow emission spectrum is $F_\nu \propto \nu^{-0.54\pm0.15}$ in the first $\sim 1300$ s after the…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Bin Liu , Wei Chen , Yun-Feng Liang , Bei Zhou , Hao-Ning He , Pak-Hin Thomas Tam , Lang Shao , Zhi-Ping Jin , Yi-Zhong Fan , Da-Ming Wei

Chandra X-ray Observatory observations of the powerful, peculiar radio galaxy 3C123 have resulted in an X-ray detection of the bright eastern hotspot, with a 1-keV flux density of ~ 5 nJy. The X-ray flux and spectrum of the hotspot are…

Astrophysics · Physics 2009-11-06 M. J. Hardcastle , M. Birkinshaw , D. M. Worrall

Due to its powerful radiation over the entire electromagnetic spectrum and its radio jet activity, the blazar 3C273 offers the opportunity to study the physics of $\gamma$-ray emission from active galactic nuclei. Since a historically…

High Energy Astrophysical Phenomena · Physics 2020-04-22 Dae-Won Kim , Sascha Trippe , Evgeniya V. Kravchenko

We report the detection of significant $\gamma$-ray emission with $\it Fermi$-LAT from the radio-quiet Seyfert 2 galaxy NGC 3281, with a luminosity of $5.9\,(\pm 1.7)\times10^{41}\rm\,erg\,s^{-1}$ at a significance of $6.22\,\sigma$ (TS =…

High Energy Astrophysical Phenomena · Physics 2025-09-29 Jun-Rong Liu , Hua Feng , Jian-Min Wang

Analysis is presented on 15 months of data taken with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope for 11 non-blazar AGNs, including 7 FRI radio galaxies and 4 FRII radio sources consisting of 2 FRII radio galaxies…

High Energy Astrophysical Phenomena · Physics 2017-02-22 LAT Collaboration

The Fermi Large Area Telescope (LAT) observed two bright X-class solar flares on 2012 March 7, and detected gamma-rays up to 4 GeV. We detected gamma-rays both during the impulsive and temporally-extended emission phases, with emission…

High Energy Astrophysical Phenomena · Physics 2017-02-22 LAT collaboration

Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2m^2 sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient…

High Energy Astrophysical Phenomena · Physics 2009-06-19 LAT Collaboration

Observations by the Large Area Telescope (LAT) on the \textit{Fermi} mission of diffuse $\gamma$-rays in a mid-latitude region in the third quadrant (Galactic longitude $l$ from $200\arcdeg$ to $260\arcdeg$ and latitude $| b |$ from…

High Energy Astrophysical Phenomena · Physics 2009-12-04 A. A. Abdo

Gamma-ray bursts (GRBs) that emit photons at GeV energies form a small but significant population of GRBs. However, the number of GRBs whose GeV-emitting period is simultaneously observed in X-rays remains small. We report gamma-ray…

High Energy Astrophysical Phenomena · Physics 2012-08-01 P. H. Thomas Tam , Albert K. H. Kong , Yi-Zhong Fan

The flat-spectrum radio quasar 3C 454.3 underwent an extraordinary 5-day gamma-ray outburst in November 2010 where the daily flux measured with the Fermi Large Area Telescope (LAT) at photon energies E>100 MeV reached (66+/-2) x 10^-6 ph…

High Energy Astrophysical Phenomena · Physics 2017-02-22 LAT collaboration

We investigate MeV-GeV $\gamma$-ray outbursts in 3C 273 in the frame of a time-dependent one-zone synchrotron self-Compton (SSC) model. In this model, electrons are accelerated to extra-relativistic energy through the stochastic particle…

High Energy Astrophysical Phenomena · Physics 2016-08-02 Y. G. Zheng , L. Zhang , B. R. Huang , S. J. Kang