298 articles – 2321 Notices  [english version]
 HAL : in2p3-00446920, version 1
 arXiv : 0912.0973
 Physical Review Letters 103 (2009) 251101
 Fermi Large Area Telescope Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes
 Fermi-LAT Collaboration(s)
 (18/12/2009)
 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 Observatory indicated excess gamma-ray emission > 1 GeV relative to diffuse Galactic gamma-ray emission models consistent with directly measured CR spectra (the so-called EGRET GeV excess''). The excess emission was observed in all directions on the sky, and a variety of explanations have been proposed, including beyond-the-Standard-Model scenarios like annihilating or decaying dark matter. The Large Area Telescope (LAT) instrument on the Fermi Gamma-ray Space Telescope has measured the diffuse gamma-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements of the diffuse gamma-ray emission for energies 100 MeV to 10 GeV and Galactic latitudes 10 deg. <= |b| <= 20 deg. The LAT spectrum for this region of the sky is well reproduced by a diffuse Galactic gamma-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.
 Thème(s) : Physique/Astrophysique/Phénomènes cosmiques de haute energiePlanète et Univers/Astrophysique/Phénomènes cosmiques de haute energie
 Lien vers le texte intégral : http://fr.arXiv.org/abs/0912.0973
 in2p3-00446920, version 1 http://hal.in2p3.fr/in2p3-00446920 oai:hal.in2p3.fr:in2p3-00446920 Contributeur : Virginie Mas <> Déposé pour le compte de : David Smith <> Soumis le : Mercredi 13 Janvier 2010, 16:46:18 Dernière modification le : Mercredi 13 Janvier 2010, 16:49:27