Gamma-ray Observations of the Galactic Plane at Energies E > 500 GeV

Abstract

In 1998 and 1999 the Whipple Observatory 10 m telescope was used to search for diffuse gamma ray emission from the Galactic Plane. No signifiant evidence of emission was found. Assuming the TeV emission profile matches EGRET observations above 1 GeV with a differential spectral index of 2.4, we derive an upper limit of {$3.0\cdot 10^{-8}\mathrm{c}{\mathrm{m}}^{-2}{\mathrm{s}}^{-1}\mathrm{s}{\mathrm{r}}^{-1}$} for the average diffuse emission above {$500GeV$} in the galactic latitude range from {$-2^{\mathrm{o}}$ to $+2^{\mathrm{o}}$} at galactic longitude {$40^{\mathrm{o}}$}. Comparisons with EGRET observations provide a lower limit of 2.31 for the differential spectral index of the diffuse emission, assuming there is no break in the spectrum between 30 GeV and 500 GeV. This constrains models for diffuse emission with a significant inverse Compton contribution.

arXiv comment18 pages, 9 figures, other comments

References in corpus (5)

• Diffuse continuum gamma rays from the Galaxy
• Electron acceleration in SNR and diffuse gamma-rays above 1 GeV
• Anisotropic inverse Compton scattering in the Galaxy
• Constraints on Gamma-ray Emission from the Galactic Plane at 300 TeV
• Cosmic ray electrons and the diffuse gamma ray spectrum

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