Related papers: On the gamma-ray emission from 3C 120
We report on a detailed investigation of the $\gamma$-ray emission from 26 non-blazar AGNs based on the Fermi LAT data accumulated for 7 years. The photon index of non-blazar AGNs changes in the range of 1.84-2.86 and the flux varies from a…
We report on measurements of the cosmic-ray induced gamma-ray emission of Earth's atmosphere by the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. The LAT has observed the Earth during its commissioning phase and with a…
We report on broadband observations of CTA 102 ($z=1.037$) during the active states in 2016-2017. In the $\gamma$-ray band, Fermi LAT observed several prominent flares which followed a harder-when-brighter behavior: the hardest photon index…
Over the last few years, the data obtained using the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope has provided new insights on high-energy processes in globular clusters, particularly those involving compact objects…
We analyzed 199 GRBs detected by Fermi-LAT during the years 2008-2019. We found 67 photons at energies >=10 GeV, which come from 34 GRBs. Out of these 34 GRBs, Fermi-LAT detects significant (TS>=4) afterglow 0.1-200 GeV photons from 25…
The recent discovery of the gamma-ray emission from the lobes of the closest radio galaxy Centaurus A by Fermi implies the presence of high-energy electrons at least up to gamma ~ 10^5 - 10^6. These high-energy electrons are required to…
We report results of an 18 ks exposure with the ACIS instrument on Chandra of the powerful z = 0.62 radio galaxy 3C 220.1. The X-ray emission separates into cluster gas of emission-weighted kT ~ 5 keV and 0.7-12 keV luminosity (to a radius…
3C 207 is a lobe-dominant radio galaxy with one sided jet and the bright knots in kpc-Mpc scale were resolved in the radio, optical and X-ray bands. It was confirmed as a gamma-ray emitter with Fermi/LAT, but it is uncertain whether the…
Using the Rossi X-ray Timing Experiment (RXTE), we have observed both the Seyfert 1 galaxy Akn 120 and the broad-line radio galaxy 3C 120. Monitoring observations spanning 2 years plus intensive stares spanning several days have been…
A multiwavelength temporal and spectral analysis of flares of 3C 279 during November 2017--July 2018 are presented in this work. Three bright gamma-ray flares were observed simultaneously in X-ray and Optical/UV along with a prolonged…
IC 310 has recently been identified as a gamma-ray emitter based on observations at GeV energies with Fermi-LAT and at very high energies (VHE, E > 100 GeV) with the MAGIC telescopes. Despite IC 310 having been classified as a radio galaxy…
We report on the first Fermi Large Area Telescope (LAT) measurements of the so-called "extra-galactic" diffuse gamma-ray emission (EGB). This component of the diffuse gamma-ray emission is generally considered to have an isotropic or nearly…
Recently, tentative evidence for an excess of gamma rays at energies around 130 GeV has been reported from analyses of data from the Fermi Large Area Telescope (LAT). The excess is potentially of great interest, as it could be associated…
We report on the detection of a gamma-ray source at the position of the nearby star-forming galaxy (SFG) M83, which is found from our analysis of 14 years of the data obtained with the Large Area Telescope (LAT) on-board {\it Fermi…
The detection of diffuse radio emission associated with clusters of galaxies indicates populations of relativistic leptons infusing the intracluster medium. Those electrons and positrons are either injected into and accelerated directly in…
We conducted a detailed long-term spectral and temporal study of flat spectrum radio quasar 4C +01.02, by using the multi-wavelength observations from Fermi-LAT, Swift-XRT, and Swift-UVOT. The $2$-day bin $\gamma$-ray lightcurve in the…
We have measured the gamma-ray emission spectrum of the Moon using the data collected by the Large Area Telescope onboard the Fermi satellite during its first 7 years of operation, in the energy range from 30 MeV up to a few GeV. We have…
A well-known calibrator source in radio astronomy, 3C 286 ($z=0.85$), is a compact steep-spectrum (CSS) radio source and spectroscopically classified as a narrow-line Seyfert 1 (NLS1) galaxy. It is also known for its damped Ly$\alpha$…
The flat spectrum radio quasar 3C 279 was observed in an extremely high activity state on June 16, 2015 (MJD 57189). In this paper, we investigate the properties of this flaring episode in the high energy $\gamma$-ray and optical bands…
We report the first detection of GeV gamma-ray flaring activity from the compact symmetric object (CSO)-like source 4C 76.03, based on 17 years of Fermi-LAT observations. Its long-term, time-averaged gamma-ray properties are consistent with…