\begin{table}%t4
\caption{\label{tab:lines}Emission line parameters for all observations, fluxes are corrected for Galactic absorption.}             % title of Table
%\centering
                          % used for centering table
\begin{tabular}{c@{~}c@{~}c@{~}c@{~}c}        % centered columns (4 columns)
\hline\hline   
\noalign{\smallskip}                  % inserts double horizontal lines
Line & Observation& Wavelength  & Flux 					& {\it FWHM}  \\
         &		       &  ($\AA$)        & (ph m$^{-2}$ s$^{-1}$)      &  ($\AA$) \\
\hline                        % inserts single horizontal line
   \ion{O}{vii} r & 1 & 21.602 (f)  & 3.0 $\pm$ 0.4 &  0.8 (f)\\      % inserting body of the table
   \ion{O}{vii} r & 2 & 21.602 (f) & 2.3 $\pm$ 0.6&  0.8 (f)\\      % inserting body of the table
   \ion{O}{vii} r & 3 & 21.602 (f)  & 2.3 $\pm$ 0.5 &  0.8 (f)\\      % inserting body of the table
   \ion{O}{vii} r & all & 21.602 (f)  & 2.4 $\pm$ 0.3&  0.8 (f)\\      % inserting body of the table
\hline                               %inserts single line
   \ion{N}{vii} Ly$\alpha$  & 1 & 24.78 (f) & 1.0 $\pm$ 0.3 & 0.8 (f) \\
   \ion{N}{vii} Ly$\alpha$  & 2 & 24.78 (f) & 0.8 $\pm$ 0.4 & 0.8 (f)\\
   \ion{N}{vii} Ly$\alpha$  & 3 & 24.78 (f) & 1.0 $\pm$ 0.4 & 0.8 (f)\\
   \ion{N}{vii} Ly$\alpha$  & all & 24.78 (f) & 1.1 $\pm$ 0.2 & 0.8 (f)\\
\hline
   \ion{O}{vii} f & 1 & 22.07 $\pm$ 0.01 & 0.6 $\pm$ 0.2 & -- \\
   \ion{O}{vii} f & 2 & 22.07 $\pm$ 0.03 & 0.2 $\pm$ 0.2 & -- \\
   \ion{O}{vii} f & 3 & 21.99 $\pm$ 0.02 & 1.0 $\pm$ 0.5 & -- \\
   \ion{O}{vii} f & all & 21.99 $\pm$ 0.02 & 0.30 $\pm$ 0.11 & -- \\   
\hline
\end{tabular}
\tablefoot{\tablefoottext{1}{The (f) indicates that the parameter was kept fixed.}}\vspace*{-2mm}
\end{table}