Modelling the interstellar radiation field of the Milky Way at parsec scale resolution at its effect on cosmic ray electrons

The interstellar radiation field (ISRF) is the result of emission by stars, and the scattering, absorption, and re-emission of absorbed starlight by dust in the interstellar medium (ISM). Current state-of-the-art 3D models for the ISRF have been developed using spatially smooth distributions for stars and dust in the Milky Way. Recently, spatial reconstructions of the dust distribution have been made using stellar extinction data that now probe down to parsec scales nearby the Solar system. Moreover, the distribution of hot, luminous OB stars has been obtained with high degree of completeness out to $\sim$2--3~kpc from the Solar system. We describe our new models that incorporate these features into the 3D models that we formerly developed using only the smooth spatial distributions. The new ISRF models have a significant degree of inhomogeneity in the distribution of the spectral intensities, particularly at ultraviolet and infrared frequencies. Comparison with multi-wavelength data shows good agreement with the new model predictions.