the map is better sampled in the center than at the edges, resulting in noise at the edges that can be mistaken for real emission. To compensate for this, we used “imagetool,” a tool available as part of the CRUSH package, to eliminate the regions of each map that had a total integration time less than 25% of the maximum. This eliminates most, but not all, of the spurious edge emission.

After removing the poorly sampled map edges, we used Starlink’s “stats” package to assess the 1$\sigma$ RMS noise of the map, calculated using all of the pixels in the off-source regions. Because this calculation includes all off-source pixels with total integration time greater than 25% of the maximum, the RMS noise can be biased by the pixels with total integration times only slightly greater than 25% of the maximum. To investigate this, we used the feature of GAIA[^6] that allows for the calculation of statistics in any user-defined region to assess the RMS noise of off-source pixels in the most well-sampled regions possible. We conclude that the 1$\sigma$ RMS in the fully-sampled, central regions of the maps may be up to a factor of two lower than the values 