LAT Background Models
| Galactic diffuse model |
gll_iem_v02.fit |
|---|---|
| Isotropic spectral template (all) |
isotropic_iem_v02.txt |
| Isotropic spectral template (front) |
isotropic_iem_front_v02.txt |
| Isotropic spectral template (back) |
isotropic_iem_back_v02.txt |
| Detailed description | Model Description |
Details on gll_iem_v02
The model for the Galactic diffuse emission was developed using spectral line surveys of H I, CO (as a tracer of H2) to derive the distribution of interstellar gas in Galactocentric rings. Infrared tracers of dust column density were used to correct column densities in directions where the optical depth of H I was either over or under-estimated. The model of the diffuse gamma-ray emission was then constructed by fitting the gamma-ray emissivities of the rings in several energy bands to the LAT observations. The fitting also required a model of the inverse Compton emission calculated using GALPROP (Strong et al. ref) and a model for the isotropic diffuse emission.
The isotropic diffuse emission was fit to the LAT data using an analysis of the sky above |b| = 30° and includes the significant contribution of residual (misclassified) cosmic rays at high energies for the current (Pass 6) instrument response functions. The table above also includes a document that provides more details.