Local analyses of Planck maps with Minkowski Functionals
  Minkowski Functionals (MF) are excellent tools to investigate the statistical
properties of the cosmic background radiation (CMB) maps. Between their
notorious advantages is the possibility to use them efficiently in patches of
the CMB sphere, which allow studies in masked skies, inclusive analyses of
small sky regions. Then, possible deviations from Gaussianity are investigated
by comparison with MF obtained from a set of Gaussian isotropic simulated CMB
maps to which are applied the same cut-sky masks. These analyses are sensitive
enough to detect contaminations of small intensity like primary and secondary
CMB anisotropies. Our methodology uses the MF, widely employed to study
non-Gaussianities in CMB data, and asserts Gaussian deviations only when all of
them points out an exceptional $\chi^2$ value, at more than $2.2 \sigma$
confidence level, in a given sky patch. Following this rigorous procedure, we
find 13 regions in the foreground-cleaned Planck maps that evince such high
levels of non-Gaussian deviations. According to our results, these non-Gaussian
contributions show signatures that can be associated to the presence of hot or
cold spots in such regions. Moreover, some of these non-Gaussian deviations
signals suggest the presence of foreground residuals in those regions located
near the galactic plane. Additionally, we confirm that most of the regions
revealed in our analyses, but not all, have been recently reported in studies
done by the Planck collaboration. Furthermore, we also investigate whether
these non-Gaussian deviations can be possibly sourced by systematics, like
inhomogeneous noise and beam effect in the released Planck data, or perhaps due
to residual galactic foregrounds.
