The Gev Excess Shining Through PDF Download

Future GeV {gamma}-ray missions, efforts to improve the diffuse {gamma}-ray emission modeling, and possible exploitation of temporal variability for source characterization are reviewed. GLAST-LAT with its improved point-spread-function is expected to attain mCrab sensitivity, facilitate identification of {gamma}-ray sources with those in other wavelength, and discover new source classes. However these new sources are likely to suffer from the Galactic diffuse background and/or the source confusion. Accurate modeling of the background will be essential to enhance discovery potential for Galactic sources and full exploitation of temporal variability will allow source identification even in highly confusing environment. GALPROP by Strong and Moskalenko provides a platform on which models and measurements on the cosmic ray, ISM and radiation field can be combined in a consistent way. An up-to-date high-energy pp interaction modeling has reduced the ''GeV Excess'' in the diffuse {gamma}-ray spectrum significantly. Updating GALPROP with this interaction modeling as well as with other improvements will be needed before GLAST goes to orbit. The new temporal domain will be fully explored by GLAST-LAT as a new way to identify and characterize AGNs at cosmological distance.