Related papers: Gamma-ray detection toward the Coma cluster with F…
Star formation in galaxies is observed to be associated with gamma-ray emission. The detection of gamma rays from star-forming galaxies by the Fermi Large Area Telescope (LAT) has allowed the determination of a functional relationship…
The gamma-ray sky >100 MeV is dominated by the diffuse emissions from interactions of cosmic rays with the interstellar gas and radiation fields of the Milky Way. Observations of these diffuse emissions provide a tool to study cosmic-ray…
The observed multi-GeV gamma-ray emission from the solar disk --- sourced by hadronic cosmic rays interacting with gas, and affected by complex magnetic fields --- is not understood. Utilizing an improved analysis of the Fermi-LAT data that…
Spatial variations of the average properties that characterize the hadronic component of the diffuse Galactic cosmic-ray sea, in particular the spectral slope and normalization, may unveil critical information about their confinement…
We investigate the contribution of the beamed jet component to the high energy emission in young and compact extragalactic radio sources, focusing for the first time on the gamma-ray band. We derive predictions on the gamma-ray luminosities…
Following evidence for an east--west elongated virial ring around the Coma galaxy cluster in a $\sim220$ GeV VERITAS mosaic, we search for corresponding signatures in $>$GeV $\gamma$-rays from Fermi-LAT, and in soft, $\sim0.1$ keV X-rays…
The Fermi-LAT data revealed giant bubbles of emission above and below the Galactic plane with an energy spectrum significantly harder than seen from other directions. How the bubbles connect to the Galactic plane is unclear. We find that…
Galaxy clusters are predicted to produce gamma-rays through cosmic ray interactions and/or dark matter annihilation, potentially detectable by the Fermi Large Area Telescope (Fermi-LAT). We present a new, independent stacking analysis of…
The $\gamma$-ray emission from stars is induced by the interaction of cosmic rays with stellar atmospheres and photon fields. This emission is expected to come in two components: a stellar disk emission, where $\gamma$-rays are mainly…
The diffuse Galactic gamma-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray…
We report the detection of high-energy gamma rays from the quiescent Sun with the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope (Fermi) during the first 18 months of the mission. These observations correspond to…
In this paper we report the Fermi Large Area Telescope (LAT) detection of the gamma-ray emission toward the young star forming region W43. Using the latest source catalog and diffuse background models, the extended gamma-ray excess is…
It is widely accepted that cosmic rays (CRs) up to at least PeV energies are Galactic in origin. Accelerated particles are injected into the interstellar medium where they propagate to the farthest reaches of the Milky Way, including a…
We calculate the flux of radio, hard X-ray and UV radiation from clusters of galaxies as produced by synchrotron emission and Inverse Compton Scattering of electrons generated as secondaries in cosmic ray interactions in the intracluster…
We analyze 5-year (63 months) data of the Large Area Telescope on board Fermi satellite from the Coma galaxy cluster in the energy range between 100 MeV and 100 GeV. The likelihood analyses are performed with several templates motivated by…
The diffuse Galactic gamma-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray…
For more than one year the Fermi Large Area Telescope has been surveying the gamma-ray sky from 20 MeV to more than 300 GeV with unprecedented statistics and angular resolution. One of the key science targets of the Fermi mission is diffuse…
Cosmic-ray (CR) electrons and nuclei interact with the Galactic interstellar gas and produce high-energy $\gamma$ rays. The $\gamma$-ray emission rate per hydrogen atom, called emissivity, provides a unique indirect probe of the CR flux. We…
Various studies have implied the existence of a gaseous halo around the Galaxy extending out to 100 kpc. Galactic cosmic rays (CRs) that propagate to the halo, either by diffusion or by convection with the possibly existing large-scale…
We use the results from a constrained, cosmological MHD simulation of the Local Universe to predict the radio halo and the gamma-ray flux from the Coma cluster and compare it to current observations. The simulated magnetic field within the…