SIMBAD references

Observations made with Ginga, OSSE and COMPTEL provide evidence that the diffuse galactic continuum emission extends down to ∼10keV, and that the spectrum steepens below about several hundred keV. If this emission is electron bremsstrahlung, then a very large power (∼10⁴³erg/s) is required to maintain the electrons against energy losses to the interstellar medium. This exceeds by an order of magnitude the total power provided by galactic supernovae. We suggest that this power might be derived from the gravitational potential released on the passage of the ISM through galactic spiral arm compressions. Alternatively, the hard X-ray galactic continuum could be the superposition of unresolved point sources such as accreting neutron stars or black holes.