  We report and analyse the presence of foregrounds in the cosmic microwave
background (CMB) radiation associated to extended galactic halos. Using the
cross correlation of Planck and WMAP maps and the 2MRS galaxy catalogue, we
find that the mean temperature radial profiles around nearby galaxies at $cz\le
4500~\rm{km~s^{-1}}$ show a statistically significant systematic decrease of
$\sim 15~\mu \rm{K}$ extending up to several galaxy radii. This effect strongly
depends on the galaxy morphological type at scales within several tens of times
the galaxy size, becoming nearly independent of galaxy morphology at larger
scales. The effect is significantly stronger for the more extended galaxies,
with galaxy clustering having a large impact on the results. Our findings
indicate the presence of statistically relevant foregrounds in the CMB maps
that should be considered in detailed cosmological studies. Besides, we argue
that these can be used to explore the intergalactic medium surrounding bright
late-type galaxies and allow for diverse astrophysical analyses.
