Galactic distribution of supernovae and OB associations

We update and extend a previous model by Higdon and Lingenfelter for the longitudinal profile of the N II intensity in the Galactic plane. The model is based on four logarithmic spiral arms, to which features like the Local Arm and local sources are added. Connecting then the N II to the H II emission, we use this model to determine the average spatial distribution of OB associations in the Milky Way. Combined with a stellar mass and cluster distribution function, the model predicts the average spatial and temporal distribution of core-collapse supernovae in the Milky Way. In addition to this average population, we account for supernovae from observed OB associations, providing thereby a more accurate description of the nearby Galaxy. The complete model is made publicly available in the python code SNOB.