Speaker
Description
In this contribution we present studies to quantify the effects of possible biases in diffuse emission models for LAT data on point-source finding and spectral parameter extraction. In particular, 1) we examine differences in source lists obtained in a 40 degree by 40 degree region around the Galactic center (GC region) using different interstellar emission models (IEMs), 2) examine the goodness-of-fit of models of the GC region that include the IEMs as well as discrete sources, 3) use a likelihood weighting scheme to include systematic uncertainties of the IEMs in the point-source fitting. We find that almost all of the differences away from the Galactic plane (|b| > 5 degrees) are attributable to the effect of the source-detection threshold in combination with small differences in the IEMs. On the other hand, along the Galactic plane, we find that biases in the IEMs can result in clusters of spurious sources in regions where the IEMs significantly under-predict the data as well as in groups of missed sources in regions where the IEMs over-predict the data. However, we find that these effects are well mitigated by the likelihood weighting scheme.
