Spatial distribution of galactic cosmic ray sources

Different locations in the galaxy are unequally participating to the production of elements and isotopes observed at the solar system. In this work, we apply the backward Markov stochastic method to determine the abundance of each nucleus at certain energy and a single location in the galaxy. A test particle is allowed to follow a stochastic path starting from the solar system and runs backward in time till hitting the galaxy boundary. The abundance for each nucleus is recorded at certain energy and single location in the stochastic path. This method is very flexible in controlling the size of the time step, which will result in more detailed structure of different locations in the galaxy which is a very big advantage for this model, since it can reveal a lot of detailed structure in the galaxy. The presented model is also capable to find out galactic locations containing sources of production for certain nuclide.