\begin{table}%t8
%\centering
\small
\caption{Relative calibration $\mathcal{R}$ of the PSB channels
obtained from the pixel-pixel scatter plots with NSIDE~=~256 (second
column, see Sect.~\ref{subs:pixpixcal}) and from the cross-spectrum
(third column, see Sect.~\ref{subs:speccal}), using $W_1$ as the
reference channel. For $\mathcal{R}_{*W_1}^{\rm spectrum}$, 1-$\sigma$
errors are used. For $\mathcal{R}_{*W_1}^{\rm pixel}$, we also include
in the error the possible bias due to a conservative $\pm $$20\%$
error in the estimate of the noise. \label{table:pixpixcal}}
\begin{tabular}{ccc}
\hline
\hline channel & $\mathcal{R}_{*W_1}^{\rm pixel}$ &
$\mathcal{R}_{*W_1}^{\rm spectrum}$ \\ \hline  
$145W2$   & 0.956~$\pm $~0.028 & $0.9391\pm 0.0023$ \\
$145X1$ & 0.985~$\pm $~0.029 & $0.9498\pm 0.0025$\\
$145X2$ & 0.749~$\pm $~0.022 & $0.7300\pm 0.0022$\\
$145Y1$   & 0.920~$\pm $~0.030 & $0.9177\pm 0.0024$\\
$145Y2$ & 0.912~$\pm $~0.029 & $0.8918\pm 0.0030$\\
$145Z1$ & 0.674~$\pm $~0.021 & $0.6702\pm 0.0019$\\
$145Z2$ & 0.407~$\pm $~0.023 & $0.4183\pm 0.0018$\\
\hline
\end{tabular}
\par
\end{table}