Fermi LAT Weekly Data

For each week, the FSSC provides two FITS files: an all-sky file of photons containing positions, energies, etc. and a spacecraft pointing history file. The underscore separated fields in the file names indicate the file type (photon or spacecraft), the Fermi mission week (e.g., w009 = week 9), the processing version (which will change with each major reprocessing of LAT data), and a version number for the file itself.

Note that currently the data may include events from slightly after the official week boundaries, which will be reflected in the start and stop times in the table. Any "run" of LAT data the FSSC receives that starts in a given week is put into the weekly file for that week and not broken up. Note additional selections must be applied to the weekly files prior to use in a data analysis.