Speaker
Simon Michael Kunz
(KIT - Karlsruhe Institute of Technology (DE))
Description
Transport models for galactic cosmic rays depend on a large number of
parameters which are poorly known and can be constrained only through
derived quantities by comparison with the observed spectra of various
cosmic ray species. Numerical models as implemented in the DRAGON or
GALPROP code describe a multitude of observations. However, degenerate
solutions limit the predictive power of these models when applied to
other observables.
This might be improved with the more precise AMS-02 data.
We use Markov chain Monte Carlo methods to investigate wide ranges of
transport parameters. Solutions to the transport equation are obtained
numerically by using the DRAGON software. A total amount of 15 Mio.
solutions was generated. The predictions are compared to measurements of
cosmic ray protons and nuclei using data from PAMELA, ACE, CREAM,
ISOMAXX and HEAO. More than 13,000 models were found to have a maximum
deviation from the data of 1 sigma averaged over all data points.
We find that even in low dimensional models no definite solution
exists. Instead, the predictions of a multitude of strongly differing
parameter combinations are conform to current measurements. In a
subsequent analysis, the more precise AMS-02 data have been included. We
discuss the impact of the AMS-02 data on transport parameter limits and
comment on the model uncertainties originating from numerics, the gas
distribution and nuclei fragmentation cross sections.
| Registration number following "ICRC2015-I/" | 905 |
|---|---|
| Collaboration | -- not specified -- |
Primary authors
Iris Gebauer
Simon Michael Kunz
(KIT - Karlsruhe Institute of Technology (DE))
