Title: The Galactic Cosmic Ray Electron Spectrum from 3 to 70 MeV Measured by Voyager 1 Beyond the Heliopause, What This Tells Us About the Propagation of Electrons and Nuclei In and Out of the Galaxy at Low Energies,
Abstract: The cosmic ray electrons measured by Voyager 1 between 3-70 MeV beyond the
heliopause have intensities several hundred times those measured at the Earth
by PAMELA at nearly the same energies. This paper compares this new V1 data
with data from the earth-orbiting PAMELA experiment up to energies greater than
10 GeV where solar modulation effects are negligible. In this energy regime we
assume the main parameters governing electron propagation are diffusion and
energy loss and we use a Monte Carlo program to describe this propagation in
the galaxy. To reproduce the new Voyager electron spectrum, which is E-1.3,
together with that measured by PAMELA which is E-3.20 above 10 GeV, we require
a diffusion coefficient which is P 0.45 at energies above 0.5 GeV changing to a
P-1.00 dependence at lower rigidities. The entire electron spectrum observed at
both V1 and PAMELA from 3 MeV to 30 GeV can then be described by a simple
source spectrum, dj/dP P-2.25, with a spectral exponent that is independent of
rigidity. The change in exponent of the measured electron spectrum from -1.3 at
low energies to 3.2 at the highest energies can be explained by galactic
propagation effects related to the changing dependence of the diffusion
coefficient below 0.5 GeV, and the increasing importance above 0.5 GV of energy
loss from synchrotron and inverse Compton radiation, which are both E2, and
which are responsible for most of the changing spectral exponent above 1.0 GV.
As a result of the P-1.00 dependence of the diffusion coefficient below 0.5
GV that is required to fit the V1 electron spectrum, there is a rapid flow of
these low energy electrons out of the galaxy. These electrons in local IG space
are unobservable to us at any wave length and therefore form a dark energy
component which is 100 times the electrons rest energy.