We report limits on the Galactic foreground emission contribution to the Background Emission Anisotropy Scanning Telescope ( BEAST ) Ka- and Q-band CMB anisotropy maps .
We estimate the contribution from the cross-correlations between these maps and the foreground emission templates of an H { \alpha } map , a de-striped version of the Haslam et al .
408 MHz map , and a combined 100 \mu m IRAS/DIRBE map .
Our analysis samples the BEAST \sim 10 ^ { \circ } declination band into 24 one-hour ( RA ) wide sectors with \sim 7900 pixels each , where we calculate : ( a ) the linear correlation coefficient between the anisotropy maps and the templates ; ( b ) the coupling constants between the specific intensity units of the templates and the antenna temperature at the BEAST frequencies and ( c ) the individual foreground contributions to the BEAST anisotropy maps .
The peak sector contributions of the contaminants in the Ka-band are of 56.5 % free-free with a coupling constant of 8.3 \pm 0.4 \mu K/R , and 67.4 % dust with 45.0 \pm 2.0 \mu K/ ( MJy/sr ) .
In the Q-band the corresponding values are of 64.4 % free-free with 4.1 \pm 0.2 \mu K/R and 67.5 % dust with 24.0 \pm 1.0 \mu K/ ( MJy/sr ) .
Using a lower limit of 10 % in the relative uncertainty of the coupling constants , we can constrain the sector contributions of each contaminant in both maps to < 20 % in 21 ( free-free ) , 19 ( dust ) and 22 ( synchrotron ) sectors .
At this level , all these sectors are found outside of the \mid b \mid = 14.6 ^ { \circ } region .
By performing the same correlation analysis as a function of Galactic scale height , we conclude that the region within b = \pm 17.5 ^ { \circ } should be removed from the BEAST maps for CMB studies in order to keep individual Galactic contributions below \sim 1 % of the map ’ s rms .