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dc.contributor.authorAbdalla, Hassan
dc.contributor.authorBöttcher, Markus
dc.date.accessioned2017-11-02T08:25:03Z
dc.date.available2017-11-02T08:25:03Z
dc.date.issued2016
dc.identifier.citationAbdalla, H. & Böttcher, M. 2016. The effects of EBL inhomogeneity on the gamma-gamma absorption of VHE gamma-rays. 4th Annual Conference on High Energy Astrophysics in Southern Africa, 25-26 Aug 2016, Cape Town, South Africa. Proceedings of science: Article no 011. [https://pos.sissa.it/275/011/]en_US
dc.identifier.issn1824-8039 (Online)
dc.identifier.urihttp://hdl.handle.net/10394/26006
dc.identifier.urihttps://pos.sissa.it/275/011/
dc.identifier.urihttps://pos.sissa.it/275/011/pdf
dc.description.abstractVery High Energy Gamma Rays (VHE; more than 100 GeV) from Cosmological Gamma Ray Sources such as blazars can be absorbed by the Extragalactic Background light (EBL), which leads to a high-energy cut-off in blazar spectral energy distributions. However, recent observa- tions of distant gamma ray sources suggest that the universe is more transparent to VHE gamma rays than expected from our current knowledge of a homogeneous EBL. One of the possible so- lutions is the hypothesis that a reduced EBL opacity results from inhomogeneities of the EBL density in particular if the line of sight to a blazar is passing through large voids in intergalactic space. We have evaluated the inhomogeneous and anisotropic EBL density and resulting gamma- gamma opacity in such a case. We find that even a sizeable void R . 1 h − 1 Gpc or many typical voids R . 100 h − 1 Mpc located along the line of sight to a distant blazar leads to a reduction of the EBL opacity only around 15%. EBL inhomogeneities are not expected to reduce the EBL gamma-gamma opacity significantly, and alternative solutions to the problem of hard VHE spectra of blazars may be requireden_US
dc.language.isoenen_US
dc.publisherHEASAen_US
dc.titleThe effects of EBL inhomogeneity on the gamma-gamma absorption of VHE gamma-raysen_US
dc.typePresentationen_US
dc.contributor.researchID24420530 - Böttcher, Markus
dc.contributor.researchID26598973 - Abdalla, Hassan


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