# New very local interstellar spectra for electrons, positrons, protons and light cosmic ray nuclei

## TL;DR

This paper presents new, self-consistent local interstellar spectra for various cosmic ray particles by combining Voyager 1 and PAMELA data with advanced galactic propagation and solar modulation models, covering energies from 3 MeV/nuc to 100 GeV/nuc.

## Contribution

It introduces a comprehensive method to derive very local interstellar spectra for multiple cosmic ray species using combined observational data and sophisticated modeling.

## Key findings

- Derived new LIS for electrons, positrons, protons, Helium, Carbon, Boron, and Oxygen.
- Validated the models against Voyager 1 and PAMELA data across a wide energy range.
- Provided expressions for LIS applicable from 3 MeV/nuc to 100 GeV/nuc.

## Abstract

The local interstellar spectra (LIS's) for galactic cosmic rays (CR's) cannot be directly observed at the Earth below certain energies, because of solar modulation in the heliosphere. With Voyager 1 crossing the heliopause in 2012, in situ experimental LIS data below 100 MeV/nuc can now constrain computed galactic CR spectra. Using galactic propagation models, galactic electron, proton and light nuclei spectra can be computed, now more reliably as very LIS's. Using the Voyager 1 observations made beyond the heliopause, and the observations made by the PAMELA experiment in Earth orbit for the 2009 solar minimum, as experimental constraints, we simultaneously reproduced the CR electron, proton, Helium and Carbon observations by implementing the GALPROP code. Below about 30 GeV/nuc solar modulation has a significant effect and a comprehensive three-dimensional (3D) numerical modulation model is used to compare the computed spectra with the observed PAMELA spectra possible at these energies. Subsequently the computed LIS's can be compared over as wide a range of energies as possible. The simultaneous calculation CR spectra with a single propagation model allows the LIS's for positrons, Boron and Oxygen to also be inferred. This implementation of the most comprehensive galactic propagation model (GALPROP), alongside a sophisticated solar modulation model to compute CR spectra for comparison with both Voyager 1 and PAMELA observations over a wide energy range, allows us to present new self-consistent very LIS's (and expressions) for electrons, positrons, protons, Helium, Carbon, Boron and Oxygen for the energy range of 3 MeV/nuc to 100 GeV/nuc.