The Galactic contribution to high latitude diffuse γ-ray emission
نویسندگان
چکیده
Recent evidence for a large Galactic halo, based on cosmic-ray radioactive nuclei, implies a significant contribution from inverse Compton emission at high Galactic latitudes. We present predictions for the expected intensity distribution, and show that the EGRET gamma-ray latitude distribution is well reproduced from the plane to the poles. We show that the Galactic component at high latitudes may be comparable to the extragalactic emission in some energy ranges.
منابع مشابه
HIGH LATITUDE GAMMA RAYS ASSOCIATED WITH VIRGO
A more detailed analysis is made of the energy spectrum of the diffuse component of extragalactic gamma rays over the range of 0.3- 10 GeV, obtained fromthe EGRET instrument at the Compton Gamma Ray Observatory. The derived excess energy spectrum of high galactic latitude, b > 60°, using intercept method shows that it is correlated with Virgo cluster (over lsr) and average Virgo intensity i...
متن کاملDiffuse Continuum Gamma Rays from the Galaxy
We have carried out a new study of the diffuse Galactic γ-ray continuum radiation using a cosmic-ray propagation model which includes nucleons, antiprotons, electrons, positrons, and synchrotron radiation. We show that models based on locally measured electron and nucleon spectra and synchrotron constraints are consistent with γ-ray measurements in the 30 MeV – 500 MeV range, but outside this r...
متن کاملThe Case for a Low Extragalactic Gamma-ray Background
Measurements of the diffuse extragalactic γ-ray background (EGRB) are complicated by a strong Galactic foreground. Estimates of the EGRB flux and spectrum, obtained by modeling the Galactic emission, have produced a variety of (sometimes conflicting) results. The latest analysis of the EGRET data found an isotropic flux Ix = 1.45 ± 0.05 above 100 MeV, in units of 10−5 ph s−1 cm−2 sr−1. We analy...
متن کاملSe p 20 06 Contribution of unresolved point sources to the galactic diffuse emission
The detection by the HESS atmospheric Cherenkov telescope of fifteen new sources from the Galactic plane makes it possible to estimate the contribution of unresolved point sources like those detected by HESS to the diffuse Galactic emission measured by EGRET and recently at higher energies by the Milagro Collaboration. Assuming that HESS sources have all the same intrinsic lumi-nosity, the cont...
متن کاملThe Diffuse Galactic Gamma-Ray Emission Model for GLAST LAT
Diffuse emission from the Milky Way dominates the γ-ray sky. About 80% of the high-energy luminosity of the Milky Way comes from processes in the interstellar medium. The Galactic diffuse emission traces interactions of energetic particles, primarily protons and electrons, with the interstellar gas and radiation field, thus delivering information about cosmic-ray spectra and interstellar mass i...
متن کامل