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 OBassociations 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.