The FITS file contains the Fermi High-Latitude Extended Sources Catalog (FHES). It provides source extension parameters (or upper limits thereof) and additional information for objects measured in 90 months of observations with the Large Area Telescope (LAT) on board NASA's Fermi satellite.
It includes the complete analysis results for 2546 sources. The analysis and data products contained in the catalog are described in detail in the accompanying paper, which is accepted for publication in the Astrophysical Journal Supplement. The preprint of the submitted manuscript can be found here: https://arxiv.org/abs/1804.08035

We further provide the 95% lower limits on the intergalactic magnetic field (IGMF) as plain ASCII files for different assumptions on the blazar duty cycles. These correspond to the limits shown in Figure 17 (right panel) of the paper.