We present a specific periodicity of the Galaxy images in the multipole domain which can be used for separation of the cosmic microwave background ( CMB ) signal from the Galaxy and foreground component .
This method takes into consideration all the coefficients of the expansion of the signal from the sky \Delta T ( \Theta, \phi ) into spherical harmonics and dealing with combination of multipoles a _ { l,m } and a _ { l + \Delta,m } for each multipole mode ( \ell, - \ell \leq m \leq \ell ) from the whole sky without galactic cut , masks or any dissection of the whole sky into disjoint regions .
For the polar coordinate system we use particular values for \Delta = 4 n , n = 1 , 2 , ... which remove all bright point-like sources localized in the Galactic plane and strong diffused component down to the CMB level .
To illustrate that significant correlations of the point like sources and foregrounds a _ { l,m } ,a _ { l + \Delta,m } coefficients we apply this method to the WMAP Q , V and W bands in order to remove these marks of Galaxy from the maps .
We believe that our method would be useful for separation of the CMB signal from different kind of ” noises ” in the maps .