Speaker
Description
Small-scale non-Gaussianity in Galactic foregrounds is an important source of uncertainty for future CMB experiments. We investigate the statistical properties of diffuse Galactic foregrounds using Minkowski Functionals and generalized skewness–kurtosis statistics across a range of angular scales. We find a remarkably similar kurtosis-type non-Gaussian signature in synchrotron, free-free, anomalous microwave emission, and thermal dust. Focusing on thermal dust, we compare Planck GNILC and 545 GHz observations with PySM and DUSTFILAMENTS simulations and perform patch-based analyses to study the spatial distribution of the signal. While PySM reproduces the global statistical trends, it fails to capture the observed spatial variations, and DUSTFILAMENTS underestimates the measured non-Gaussianity. Using controlled toy models with different one-point PDFs and power spectra, we show that the observed behaviour naturally arises from the combination of a heavy-tailed one-point PDF and a steep dust-like power spectrum. Finally, I will discuss our ongoing efforts to improve dust simulations by incorporating observed filament structural and spectral properties.