\begin{table}%t1
\caption{Emission line fluxes in units of 
  $10^{-17}$~erg~s$^{-1}$~cm$^{-2}$. Note that both
  lines in the~$[$\ion{O}{iii}$]$ and $[$\ion{N}{ii}$]$~doublets
  were fitted together.}\label{tab:emlines}
%\centering
\small
\begin{tabular}{lccc} 
\hline \hline
 & & & \\[-8pt]
     & \multicolumn{3}{c}{Fluxes $[10^{-17}$ erg s$^{-1}$ cm$^{-2}$ $]$} \\
                             &  N5236-254   & N5236-487    & N3621-1106 \\
\hline	         
Line                         &              &              &            \\
H$\beta$ 4861                &   6.0        &  2.2         &  4.6       \\
H$\alpha$ 6562               &  18.4        & 12.3         & --0.15      \\
$[$\ion{O}{iii}$]$ 4959,5007 &   6.9, 20.6  &  4.1, 12.1   &  7.2, 21.7 \\ 
$[$\ion{N}{ii}$]$ 6548,6584  &   5.6, 16.7  &  0.7,  2.2   &  4.7, 14.1 \\
Mean error                   &   1.3        &  0.8         &  2.9       \\ 
$m_{5007}$              & $25.5\pm0.06$ & $26.1\pm0.07$ & $25.4\pm0.13$ \\
\hline
\end{tabular}
\end{table}