Motion induced second order temperature and y-type anisotropies after
  the subtraction of linear dipole in the CMB maps
  y-type spectral distortions of the cosmic microwave background allow us to
detect clusters and groups of galaxies, filaments of hot gas and the
non-uniformities in the warm hot intergalactic medium. Several CMB experiments
(on small areas of sky) and theoretical groups (for full sky) have recently
published y-type distortion maps. We propose to search for two artificial hot
spots in such y-type maps resulting from the incomplete subtraction of the
effect of the motion induced dipole on the cosmic microwave background sky.
This dipole introduces, at second order, additional temperature and
y-distortion anisotropy on the sky of amplitude few \mu K which could
potentially be measured by Planck HFI and Pixie experiments and can be used as
a source of cross channel calibration by CMB experiments. This y-type
distortion is present in every pixel and is not the result of averaging the
whole sky. This distortion, calculated exactly from the known linear dipole,
can be subtracted from the final y-type maps, if desired.
