Evidence for large scale cosmic ray electron gradients in the Galaxy.

The relationship between nonthermal radio emission of the Galaxy and the cosmic ray electron spectrum is examined emphasizing a direct comparison between the local cosmic ray electron flux deduced from measurements on earth and the average synchrotron emissivity observed in the spiral arm of the Galaxy. It is concluded that (1) the nonthermal emissivity of the Galaxy varies in a systematic way related to the structure of the spiral arms, (2) the local emissivity near the sun may be a factor of up to roughly 4 less than typical emissivities in our own spiral arm, (3) the electron spectrum producing the nonthermal emission may itself flatten at energies less than 1 GeV, thus producing a flattening in the emissivity spectrum, and (4) solar modulation effects at low energies may be much less than previously thought