\begin{table}%t1 \par \caption {\label{tab:relations}Fitting coefficients of the CMR, the magnitude-surface brightness relation, and the power-law slope~$\alpha$ of the LF, with errors given in parentheses.} %\centering \par \begin{tabular}{lrrrrrr} \hline\hline ~ & \multicolumn{2}{c}{$(V-I)_0 = A\cdot M_V + B$} && \multicolumn{2}{c}{$\mu_{V,0} = C\cdot M_V +D$} \\ \cline{2-3} \cline{5-6} ~ & $A$ & $B$ && $C$ & $D$ & $\alpha$ \\ \hline Centaurus & $-0.042$ & $0.36$ && $0.57$ & $30.85$ & $-1.14$ \\ ~ & $(0.001)$ & $(0.02)$ && $(0.07)$ & $(0.87)$ & $(0.12)$ \\ Hydra~I & $-0.044$ & $0.36$ && $0.67$ & $31.57$ & $-1.40$ \\ ~ & $(0.001)$ & $(0.01)$ && $(0.07)$ & $(0.99)$ & $(0.18)$ \\ Fornax & $-0.033$ & $0.52$ && $0.68$ & $32.32$ & $-1.33$ \\ ~ & $(0.004)$ & $(0.07)$ && $(0.04)$ & $(1.12)$ & $(0.08)$ \\ \hline \end{tabular} \end{table}