Göttingen 2012 – scientific programme

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T: Fachverband Teilchenphysik

T 91: Gammaastronomie 3

T 91.6: Talk

Wednesday, February 29, 2012, 18:00–18:15, ZHG 008

Very high energy gamma ray absorption via the Milky Way diffuse radiation field — •Andreas Maurer, Martin Raue, Tanja Kneiske, and Dieter Horns — Institut für Experimentalphysik, Luruper Chaussee 149, D-22761 Hamburg

When very high energy (VHE) gamma rays (E>100 GeV) transverse low energy photon fields, the production of electron-positron pairs leads to the attenuation of the intrinsic gamma ray flux. This phenomena is well know for VHE radiation from extragalactic sources, like eg. blazars, interacting with the cosmic infrared background.

In this contribution the absorption of galactic VHE gamma rays due to the interaction with the Milky Way diffuse radiation field is discussed. While the photon field densities inside our galaxy can be several orders of magnitude higher compared to the diffuse extragalactic flux, the distances are much shorter leading to an overall smaller effect. On the other hand, the detection of such an attenuation could be used to study the galactic IR emission, measure the distance of galactic sources, or investigate particle physics phenomena beyond the standard model. It is investigated how forthcoming imaging air Cherenkow telescopes, like CTA, and wide angle Cherenkow arrays, like HiSCORE, with their improved sensitivities up to several hundred TeV will measure this absorption feature for a large number of galactic sources.