Diffuse hard X-ray emission from the Galactic ridge

We re-analyze Ginga scanning observation data and present hard X-ray spectra and the distribution along the Galactic ridge. The spectra exhibit a hard component much in excess of single temperature thermal bremsstrahlung with kT = 5 - 10 keV, and the intensity is consistent with a power-law extension from the gamma-ray measurements. This result suggests that there is continuous emission over keV similar to GeV range from an extended region in the Galactic ridge. This implies that freshly accelerated electrons are responsible for the emission.