  As galactic halos are not directly visible, there are many ambiguities
regarding their composition and rotational velocity. Though most of the dark
matter is non-baryonic, {\it some fraction is}, and it can be used to trace the
halo rotation. Asymmetries in the CMB towards M31 had been seen in the Planck
data and ascribed to the rotational Doppler shift of the M31 halo.
Subsequently, the same methods were used in the direction of five other
galaxies belonging to the Local Group, namely M33, M81, M82, NGC 5128, and NGC
4594. It had been proved that there could be stable clouds of gas and dust in
thermal equilibrium with the CMB at 2.7 K, which had been called ``virial
clouds''. In this paper, adopting this scenerio, an attempt is made to
constrain the fraction of dust grains and gas molecules in the clouds.
