\begin{table}%T1
\par
%\centering
\par
\caption{\label{tab:he}Average of linear fits to histogram-equating curves for 1, 5, 20 and~56~min integrated MDI~magnetograms.}
%\centering
$$
\begin{tabular}{r@{ vs. }lr@{ $\pm$ }lr@{ $\pm$ }l}
\hline\hline
\multicolumn{2}{c}{Comparison} & \multicolumn{2}{c}{Intercept} & \multicolumn{2}{c}{Slope} \\
\hline
1-min MDI~& SPM~  &~$-0.261$ & 0.149 & 1.360 & 0.006 \\
5-min MDI~& SPM~  &~$-0.113$ & 0.067 & 1.268 & 0.003 \\
20-min MDI~& SPM~ &~$-0.118$ & 0.051 & 1.226 & 0.001 \\
56-min MDI~& SPM~ &~$-0.116$ & 0.051 & 1.212 & 0.002 \\
\hline
\multicolumn{6}{c}{Results of \citet{thorntonjones2002}:} \\
1-min MDI~& SPM~  & 3.837 & 1.866 & 1.362 & 0.035 \\
\hline
\end{tabular}
$$
\end{table}