30TH INTERNATIONAL COSMIC RAY CONFERENCE Coma super-cluster an origin for the highest energy protons in observed Cosmic Rays flux. P ANTEA DAVOUDIFAR 1 , SEYED JALILEDIN F ATEMI 2 , HAMID ARJOMAND KERMANI 1 1 PhD Student in Astroparticle Physics / Kerman University 2 Professor of Physics / Kerman University dfpantea@yahoo.com Abstract: In the present work, after our work about the extragalactic gamma ray flux in direction of Coma super-cluster, with considering the Virgo proton flux and considering a constant gamma to pro- ton ratio for the very high energy cosmic rays in first approximation, the extragalactic proton flux in Coma direction is calculated. We have considered the available theoretical models for gamma ray flux from Virgo supper-cluster and compared the result for Coma supper-cluster with KUO et al. model. [3] We have studied that is it possible that the coma super-cluster be an origin for the highest energy pro- tons in cosmic rays flux or not. a detailed analysis has made. Introduction The existence of the diffuse gamma ray back- ground first denoted by Kraushaar et al. on the basis of data from OSO-3 satellite. More studies did by SAS-2 satellite (Fichtel and Thompson, 1982) and EGRET (Streekumar et al. 1998). Most of the galactic gamma ray sources are in galactic plan, so the diffuse gamma ray flux in the galactic poles could be considered from extraga- lactic sources if they exist. In our first work [1,2], by using EGRET data, first we have offered an exponential flux in direction of Coma super-cluster: 4 . 0 8 . 1 , ) ( ± = ∝ − γ γ E E I 1 2 6 10 9 . 1 ~ ) 30 ( − − − × − > s cm MeV E I We concluded that in this quarter % 9 . 25 ~ ob- served total flux for MeV E 30 > originated from Coma super-cluster direction. By assuming that a part of gamma rays in a clus- ter is produced by cosmic rays hadronic interac- tions (mainly protons) with thermal ions in inter cluster medium, by using the model (Dermer, 1986) for hadronic interactions and also by con- sidering the Gamma rays production by Inverse Compton Scattering mechanism, in the work presented by KUO et al. [3] they have computed a diffuse gamma ray flux for a cluster. In figure 1, we have shown our results which is presented in our first paper in this conference [1] in comparison with KUO et al. Methods As it could be seen in figure 1, the results of KUO et al. are in the favor of the A-model results for Virgo super-cluster although the agreement re- duces by energy. The difference between Coma excess and Virgo excess in this quarter is comparable with the results of KUO et al. and this latter is in good agreement with the observations. ICRC 2007 Proceedings - Pre-Conference Edition