Astropy: background modeling for Gammapy

by mapaz for Python Software Foundation

Objective: implement the most successful background modeling methods largely in use by the gamma-ray community in the Astropy/Gammapy framework in two steps: 1 Implement tools to create background model templates from observations with no or only a few gamma-ray sources in the field of view. 2 Develop algorithms to estimate the background in observations containing gamma-ray sources using the model templates from the first step.