A Galactic Cosmic Ray Electron Intensity Increase of a factor of up to 100 At Energies between 3 and 50 MeV in the Heliosheath between the Termination Shock and the Heliopause Due to Solar Modulation As Measured by Voyager 1

TL;DR

This study measures the significant increase in galactic electron intensities, up to 100-fold, between 3 and 50 MeV in the heliosheath, revealing strong solar modulation effects observed by Voyager 1.

Contribution

It provides detailed measurements of electron intensity changes in the heliosheath, highlighting the energy-dependent spectral steepening and modulation effects due to solar activity.

Findings

Electron intensities increase up to 100 times from inner to outer heliosheath.

Spectral index steepens from -1.3 outside the termination shock to -2.5 near the heliosheath.

Large modulation effects below 100 MV suggest enhanced diffusion processes.

Abstract

We have derived background corrected intensities of 3-50 MeV galactic electrons observed by Voyager 1 as it passes through the heliosheath from 95 to 122 AU. The overall intensity change of the background corrected data from the inner to the outer boundary of the heliosheath is a maximum of a factor ~100 at 15 MeV. At lower energies this fractional change becomes less and the corrected electron spectra in the heliosheath becomes progressively steeper, reaching values ~ -2.5 for the spectral index just outside of the termination shock. At higher energies the spectra of electrons has an exponent changing from the negative LIS spectral index of -1.3 to values approaching zero in the heliosheath as a result of the solar modulation of the galactic electron component. The large modulation effects observed below ~100 MV are possible evidence for enhanced diffusion as part of the modulation process for electrons in the heliosheath.