Gamma-ray emission from the solar halo and disk: a study with EGRET data

Abstract

Context: The Sun has recently been predicted to be an extended source of gamma-ray emission, produced by inverse-Compton (IC) scattering of cosmic-ray (CR) electrons on the solar radiation field. The emission was predicted to be extended and a confusing foreground for the diffuse extragalactic background even at large angular distances from the Sun. The solar disk is also expected to be a steady gamma-ray source. While these emissions are expected to be readily detectable in the future by GLAST, the situation for available EGRET data is more challenging. Aims: The theory of gamma-ray emission from IC scattering on the solar radiation field by Galactic CR electrons is given in detail. This is used as the basis for detection and model verification using EGRET data. Methods: We present a detailed study of the solar emission using the EGRET database, accounting for the effect of the emission from 3C 279, the moon, and other sources, which interfere with the solar emission. The analysis was performed for 2 energy ranges, above 300 MeV and for 100-300 MeV, as well as for the combination to improve the detection statistics. The technique was tested on the moon signal, with our results consistent with previous work. Results: Analyzing the EGRET database, we find evidence of emission from the solar disk and its halo. The observations are compared with our model for the extended emission. The spectrum of the solar disk emission and the spectrum of the extended emission have been obtained. The spectrum of the moon is also given. Conclusions: The observed intensity distribution and the flux are consistent with the predicted model of IC gamma-rays from the halo around the Sun.

Corrected typos, added acknowledgements. A&A in press

References in corpus (10)

• Diffuse Galactic continuum gamma rays. A model compatible with EGRET data and cosmic-ray measurements
• A new determination of the extragalactic diffuse gamma-ray background from EGRET data
• Gamma-ray continuum emission from the inner Galactic region as observed with INTEGRAL/SPI
• Anisotropic inverse Compton scattering in the Galaxy
• Gamma-rays from halos around stars and the Sun
• Shining light through the Sun
• The Gamma-ray Albedo of the Moon
• Inverse Compton scattering on solar photons, heliospheric modulation, and neutrino astrophysics
• The Earth's Gamma-ray Albedo as observed by EGRET
• Extended solar emission - an analysis of the EGRET data

Cited by in corpus (68)

• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• Fermi Large Area Telescope Fourth Source Catalog
• Fermi Large Area Telescope First Source Catalog
• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• Fermi-LAT Observations of the Diffuse Gamma-Ray Emission: Implications for Cosmic Rays and the Interstellar Medium
• The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data
• The Fermi Galactic Center GeV Excess and Implications for Dark Matter
• Science with e-ASTROGAM (A space mission for MeV-GeV gamma-ray astrophysics)
• Fermi-LAT Observations of Two Gamma-Ray Emission Components from the Quiescent Sun
• Solar Gamma Rays Powered by Secluded Dark Matter
• Terrestrial and Solar Limits on Long-Lived Particles in a Dark Sector
• Gamma ray astrophysics: the EGRET results
• Solar Atmospheric Neutrinos: A New Neutrino Floor for Dark Matter Searches
• The First Fermi-LAT Solar Flare Catalog
• Constraints on Spin-Dependent Dark Matter Scattering with Long-Lived Mediators from TeV Observations of the Sun with HAWC
• First Observation of Time Variation in the Solar-Disk Gamma-Ray Flux with Fermi
• Evidence for a New Component of High-Energy Solar Gamma-Ray Production
• Fermi Gamma-ray Space Telescope: High-Energy Results from the First Year
• Search for dark matter signatures in the gamma-ray emission towards the Sun with the Fermi Large Area Telescope
• Unexpected Dip in the Solar Gamma-Ray Spectrum
• TeV Solar Gamma Rays From Cosmic-Ray Interactions
• Cosmic-ray interactions with the Sun using the FLUKA code
• Constraints on dark matter models from a Fermi LAT search for high-energy cosmic-ray electrons from the Sun
• First HAWC Observations of the Sun Constrain Steady TeV Gamma-Ray Emission
• The TeV Sun Rises: Discovery of Gamma rays from the Quiescent Sun with HAWC
• Isotropic Gamma-Ray Background: Cosmic-Ray Induced Albedo from Debris in the Solar System?
• A search for dark matter cosmic-ray electrons and positrons from the Sun with the Fermi Large Area Telescope
• Hard and bright gamma-ray emission at the base of the Fermi bubbles
• Accurate calculations of the WIMP halo around the Sun and prospects for its gamma-ray detection
• The Sun at GeV--TeV Energies: A New Laboratory for Astroparticle Physics
• Galactic Cosmic-Ray Propagation in the Inner Heliosphere: Improved Force-Field Model
• Cosmic-Ray Interactions in the Solar Atmosphere
• StellarICS: Inverse Compton Emission from the Quiet Sun and Stars from keV to TeV
• Cosmic-ray propagation around the Sun: investigating the influence of the solar magnetic field on the cosmic-ray Sun shadow
• Constraining Dark Matter Properties with Gamma-Rays from the Galactic Center with Fermi-LAT
• The Sun at TeV energies: gammas, neutrons, neutrinos and a cosmic ray shadow
• Compton scattering of blackbody photons by relativistic electrons
• Searches for neutrinos from cosmic-ray interactions in the Sun using seven years of IceCube data
• The solar disk at high energies
• Inverse Compton X-rays from relativistic flare electrons and positrons
• Hadronic Interactions of Energetic Charged Particles in Protogalactic Outflow Environments and Implications for the Early Evolution of Galaxies
• A New Component from the Quiet Sun: Synchrotron Radiation from Galactic Cosmic-Ray Electrons
• Search for gamma-ray emission from the Sun during solar minimum with the ARGO-YBJ experiment
• Yet Another Sunshine Mystery: Unexpected Asymmetry in GeV Emission from the Solar Disk
• Small-Scale Magnetic Fields are Critical to Shaping Solar Gamma-Ray Emission
• Coronal radiation belts
• Probing the cosmic ray mass composition in the knee region through TeV secondary particle fluxes from solar surroundings
• Transport of Cosmic ray electrons from 1 AU to the Sun
• A study of super-luminous stars with the Fermi Large Area Telescope
• Role of magnetic arcades in explaining the puzzle of the gamma-ray emission from the solar disk
• Possible detection of gamma rays from Epsilon Eridani
• Constraining the extension of a possible gamma-ray halo of 3C 279 from 2008-2014 solar occultations
• A software package for stellar and solar inverse-Compton emission: Stellarics
• Anisotropic Photon and Electron Scattering without Ultrarelativistic Approximation
• How the dynamical properties of globular clusters impact their $\gamma$-ray and X-ray emission
• High energy radiation from luminous and magnetized stars
• Gamma-ray halo around 3C 279: looking through the Sun on the 8th of October
• Simulating gamma-ray production from cosmic rays interacting with the solar atmosphere in the presence of coronal magnetic fields
• Multi-frequency test of dark matter annihilation into long-lived particles in Sirius
• Puzzling Variation of Gamma Rays from the Sun over the Solar Cycle Revealed with Fermi-LAT
• First Observations of Solar Halo Gamma Rays Over a Full Solar Cycle
• Angular Distribution of Gamma Rays Produced in Proton-Proton Collisions
• Solar gamma ray probe of local cosmic ray electrons
• Lunar gamma-ray emission observed by FERMI
• Constraints on dark matter scattering with long lived mediators from observations of the Sun with the Fermi Large Area Telescope
• Diffuse continuum emission and large extended sources at MeV energies
• Exploring the nature of Galactic unassociated sources detected by the Fermi-LAT
• A 3D Monte Carlo calculation of the inverse Compton emission from the Sun and stars in presence of magnetic and electric fields