دانلود رایگان مقاله SOLARPROP: مدولاسیون خورشیدی وابسته Charge-sign برای همه

Abstract

We present SOLARPROP, a tool to compute the influence of charge-sign dependent solar modulation for cosmic ray spectra. SOLARPROP is able to use the output of popular tools like GALPROP or DRAGON and offers the possibility to embed new models for solar modulation. We present some examples for proton, antiproton and positron fluxes in the light of the recent PAMELA and AMS-02 data.

6. Conclusions

We have introduced a tool called SOLARPROP to simulate charge-sign dependent solar modulation for cosmic rays. This is an advantage to the commonly used force-field approximation, as also drift effects which are charge-sign dependent are taken into account. We have validated the tool against several simple models from the literature, to show that the software works as expected. A more sophisticated two dimensional model has also been implemented. The only required input for this model is a date or a time period. With this information and a local interstellar flux, SOLARPROP calculates the top of the atmosphere flux. The results have been compared with several proton and antiproton data sets from BESS, BESS-Polar and PAMELA and are in a good agreement. The comparison with positron data from PAMELA and AMS-02 is more challenging. We find some tension with the data, which probably show that the implemented model is too simple to account for solar modulation for leptons. On the other hand also the local interstellar flux for positrons is rather uncertain due to its possible primary component. SOLARPROP has the advantage that it can be easily extended by new models. The implementation of custom models will make it possible to test further models for leptons. This is left for future work. Another advantage of SOLARPROP is its FITS interface. With this interface, output from popular tools for the propagation of cosmic rays in the galaxy like GALPROP and DRAGON can directly be used as input for SOLARPROP. In the past, the free Fisk potential in the force-field method was often degenerate with fit parameters from galaxy propagation of cosmic rays like the strength of reacceleration. We hope that SOLARPROP can help to break this degeneracy and will lead in the combination with a detailed study of cosmic ray transport in the galaxy to a smaller propagation uncertainty at GeV kinetic energies. This is important for indirect dark matter detection with antiprotons and positrons and will hopefully be useful in the near future.