12-20 July 2017
BEXCO
Asia/Seoul timezone
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Contribution

BEXCO - Room A(101/102)

[CRD004] New self-consistent local interstellar spectra for electrons, positrons, protons, Helium and Carbon computed from Voyager 1 a

Speakers

  • Driaan BISSCHOFF

Primary authors

Co-authors

Description

The comparison of computed galactic spectra with in situ experimental data at lower energies is possible with observations made by the Voyager 1 spacecraft outside the dominant modulating influence of the heliosphere. Galactic spectra computed by galactic propagation models and considered to be local interstellar spectra (LIS's), for specifically electrons, protons, Helium and Carbon nuclei, can now be compared with observations at low energies (less than 100 MeV/nuc) from Voyager 1 and at high energies (above 30 GeV/nuc) from the PAMELA space detector at the Earth. We set out to reproduce the Voyager 1 observations beyond the heliopause using the GALPROP code and the PAMELA spectra at the Earth via a comprehensive solar modulation model. With these models and observations we also infer a positron LIS. By varying the galactic diffusion parameters in the GALPROP model, specifically the rigidity dependence of spatial diffusion, and then including reacceleration and convection in Galactic space, we compute spectra simultaneously for galactic electrons, positrons, protons, Helium and Carbon. These LIS are then used as input to a full 3D solar modulation model to test the spectra against the PAMELA spectra. We present new LISs with expressions for the energy range of 3 MeV/nuc to 100 GeV/nuc.