\begin{table}%t2
\caption{Strongest detected water emission lines. Various spectroscopic characteristics of the detected lines are also provided.
  The last column lists estimates of the critical density
  $n_{{\rm crit}}$ assuming $T_{{\rm gas}}=1000$~K and $\sigma
  \simeq 10^{-15}$~cm$^{-2}$.
  \label{table_strongest_lines}}
  %\centerline
{
\begin{tabular}{llllllll}
\hline\hline
\multicolumn{1}{c}{Line}& \multicolumn{1}{c}{Nuclear state} &\multicolumn{1}{c}{Transition(u$\rightarrow$l)} & \multicolumn{1}{c}{Wavelength} & \multicolumn{1}{c}{$E_{{\rm upper}}$} & \multicolumn{1}{c}{$E_{{\rm lower}}$}&\multicolumn{1}{c}{$A_{{\rm ul}}$}&\multicolumn{1}{c}{$n_{{\rm crit}}$}\\
 & & \multicolumn{1}{c}{$(v_1 v_2 v_3)\ J\ K_a K_c\ -\ (v_1' v_2' v_3')\ J'\ K_a' K_c'$} & \multicolumn{1}{c}{(micron)} & \multicolumn{1}{c}{(cm$^{-1}$)} & \multicolumn{1}{c}{(cm$^{-1}$)} & \multicolumn{1}{c}{(s$^{-1}$)}&\multicolumn{1}{c}{(cm$^{-3}$)} \\
\hline
1....... & ortho-H$_2$O & \ \ \ \ (001) 15 \ 6 10--(000) 14 \ 4 11           & 2.28020     & 7131.63 & 2746.02 & 9.50~$\times$~10$^{-2}$    & 9.50~$\times$~10$^{8}$\\
2....... & ortho-H$_2$O & \ \ \ \ (001) 15 \ 7 \phantom{1}9--(000) 14 \ 5 10           & 2.28076$^{(1)}$ & 7302.72 & 2918.24 & 8.88~$\times$~10$^{-2}$& 8.88~$\times$~10$^{8}$\\
3....... & ortho-H$_2$O & \ \ \ \ (001) 16 \ 5 11--(000) 15 \ 3 12           & 2.28093$^{(1)}$ & 7464.48 & 3080.18 & 8.27~$\times$~10$^{-2}$& 8.27~$\times$~10$^{8}$\\
4....... & ortho-H$_2$O & \ \ \ \ (001) 14 \ 8 \phantom{1}6--(000) 13 \ 6 \phantom{1}7 & 2.28449$^{(1)}$ & 7133.78 & 2756.41 & 6.56~$\times$~10$^{-2}$& 6.56~$\times$~10$^{8}$\\
5....... & ortho-H$_2$O & \ \ \ \ (100) 18 \ 7 12--(000) 17 \ 4 13           & 2.28462$^{(1)}$ & 8394.96 & 4017.90 & 2.00~$\times$~10$^{-1}$& 2.00~$\times$~10$^{9}$\\
6....... & ortho-H$_2$O & \ \ \ \ (001) 12 \ 9 \phantom{1}3--(000) 11 \ 7 \phantom{1}4 & 2.28694    & 6694.58 & 2321.90 & 1.88~$\times$~10$^{-2}$    & 1.88~$\times$~10$^{8}$\\
7....... & ortho-H$_2$O & \ \ \ \ (001) 14 \ 5 10--(000) 13 \ 3 11           & 2.28744     & 6619.79 & 2248.06 & 6.24~$\times$~10$^{-2}$    & 6.24~$\times$~10$^{8}$\\
8....... & ortho-H$_2$O & \ \ \ \ (001) 13 \ 8 \phantom{1}6--(000) 12 \ 6 \phantom{1}7 & 2.29036     & 6799.95 & 2433.80 & 4.65~$\times$~10$^{-2}$    & 4.65~$\times$~10$^{8}$\\
9....... & ortho-H$_2$O & \ \ \ \ (001) 13 \ 4 10--(000) 12 \ 2 11           & 2.29134     & 6139.03 & 1774.75 & 3.20~$\times$~10$^{-2}$    & 3.20~$\times$~10$^{8}$\\
10.....  & ortho-H$_2$O & \ \ \ \ (001) 18 \ 7 11--(000) 17 \ 5 12           & 2.29180     & 8537.65 & 4174.38 & 3.21~$\times$~10$^{-1}$    & 3.21~$\times$~10$^{9}$\\ 
\hline
\end{tabular}  }
\smallskip
{\em Note} $^1$ Blended lines.
\end{table}