\begin{table}%t1
%\centering
\par
\caption{\label{tab:lines}Observed HDO lines used in the modeling.}
\par
\begin{tabular}{rccrlc}
\hline \hline\noalign{\smallskip}
& $J_K$  &  $\nu$ & $E_{\rm l}/k$  &  Telescope   &  Ref.  \\
& & (GHz)   & (K) & &   \\
\hline   
1 & $3_{1,2}{-}3_{1,3}$ &  481.8  &  144.5 &   HIFI & \tablefootmark{a}\\
2 & $2_{0,2}{-}1_{1,1}$ &  490.6 &  42.9 &    HIFI & \tablefootmark{a} \\
3 & $1_{1,0}{-}1_{0,1}$ &   509.2  &  22.3               &     HIFI           & \tablefootmark{a}  \\
4 & $2_{2,0}{-}3_{0,3}$              &    537.8  &  131.4              &   HIFI              & \tablefootmark{a}\\
5 & $2_{1,1}{-}2_{0,2}$              &    599.9 &    66.4              &    HIFI              & \tablefootmark{a}\\
\hline\noalign{\smallskip}
6 &  $1_{1,0}{-}1_{1,1}$             &  80.6       &  42.9               & IRAM 30-m   & \tablefootmark{b}\\
7 & $3_{1,2}{-} 2_{2,1}$              &   225.9 &  156.7              &  IRAM 30-m      & \tablefootmark{c}\\
8 & $2_{1,1}{-}2_{1,2}$               &   241.6 &    83.6            & SEST                & \tablefootmark{d} \\
9 & $1_{0,1}{-}0_ {0,0}$              &   464.9 &     0.0              & CSO                 & \tablefootmark{e} \\
10 & $1_{1,1}{-}0_{0,0}$               &   893.6 &     0.0           & CSO                 & \tablefootmark{f} \\
\hline
\end{tabular}
\vspace*{-1.5mm}
\tablefoot{Rows 1 through 5: summary of all the HDO transitions observed in the HIFI bands 1a and 1b towards Sgr B2(M) (this work). Rows 6 through 9: list of previously observed HDO features that were used to constrain the results of our model (see Sect.~\ref{results}).} 
\vspace*{-1.5mm}
\tablebib{\tablefoottext{a}{this work;} 
\tablefoottext{b}{Belloche et~al., in prep;} 
\tablefoottext{c}{\citet{Jacq1990};} 
\tablefoottext{d}{\citet{Nummelin1998};} 
\tablefoottext{e}{M. Gerin, priv. comm.;} 
\tablefoottext{f}{ \citet{Comito2003}.}}
\vspace*{8mm}
\end{table}