\begin{table}%t10
%\centering
\par
\caption{Electron temperature indicators in NGC~6153.}\label{t10}
%\begin{flushleft}
\begin{tabular}{lcccc}
\hline
\hline
Ion & Ioniz. & Lines& Observed & $T_{{\rm e}}$\\
 & pot. (eV)& used &ratio  & (K) \\
\hline
\ion{[N}{ii]} & 14.5 & 5755/6584 & 0.017 & 9600\\
\ion{[S}{iii]} & 23.3 & 6312/18.7 & 0.016 & 8000 \\
\ion{[Ar}{iii]} & 27.6 & 7136/8.99 & 0.342 & $\leq$7000\\
\ion{[O}{iii]} & 35.1 & 4363/5007 & 0.0047 & 9030\\
\ion{[O}{iii]} & 35.1 & 5007/52  & 3.6 & 7800\\
\ion{[O}{iii]} & 35.1 & 1663/5007  & $\leq$0.00159 & $\leq$7900\\
\ion{[Ne}{iii]} & 41.0 & 3868/15.5 & 0.290 & 8200\\
\hline
\end{tabular}
\end{table}