\begin{table}%t3
\caption{\label{hyd_tab}Parameters of VLBA 1.665~GHz hydroxyl maser features.}
%\centering
\par
\begin{tabular}{c c c c c c r r c c c}
\hline \hline \noalign{\smallskip}
Feature & \multicolumn{2}{c}{$V_{\rm LSR}$ } & \multicolumn{2}{c}{$F_{\rm peak}$}  & & \multicolumn{1}{c}{$\Delta x$} & \multicolumn{1}{c}{$\Delta y$} & & $\Delta V_{\rm z}$\tablefootmark{a} & $B_{\rm z}$  \\
        & \multicolumn{2}{c}{(km s$^{-1}$)} & \multicolumn{2}{c}{(Jy beam$^{-1}$)} & & \multicolumn{1}{c}{(mas)} & \multicolumn{1}{c}{(mas)} & & (km s$^{-1}$)    & (mG) \\
        &     RCP          &       LCP       &     RCP          &       LCP   & &            &           & & & \\
\hline
1   & 70.88 & 71.76 & 2.39 & 0.40 & &$            0         $ & $            0         $ & & $ -0.86 $ & $ -1.5 $ \\
2   & 67.89 & ...   & 2.02 & ...  & &$ -210.26 \pm 1.07 $ & $  178.74 \pm 0.77 $ & & ... & ... \\
3   & 66.84 & 66.84 & 1.36 & 0.84 & &$   14.24 \pm 0.62 $ & $   18.87 \pm 0.77 $ & & ... & ... \\
4   & 73.87 & 73.87 & 1.01 & 0.16 & &$ -251.52 \pm 0.78 $ & $   88.39 \pm 1.47 $ & & ... & ... \\
5   & ...   & 74.75 & ...  & 0.97 & &$ -385.08 \pm 1.46 $ & $  203.14 \pm 1.00 $ & & ... & ... \\
6   & ...   & 70.57 & ...  & 0.89 & &$  199.12 \pm 1.45 $ & $  174.08 \pm 1.13 $ & & ... & ... \\
7   & 68.07 & ...   & 0.74 & ...  & &$ -185.97 \pm 0.67 $ & $  191.75 \pm 1.29 $ & & ... & ... \\
8   & 72.99 & 72.99 & 0.67 & 0.26 & &$   57.29 \pm 0.71 $ & $  119.21 \pm 0.94 $ & & ... & ... \\
9   & ...   & 75.10 & ...  & 0.60 & &$ -297.88 \pm 1.46 $ & $  130.40 \pm 1.14 $ & & ... & ... \\
10  & 74.92 & ...   & 0.55 & ...  & &$ -358.64 \pm 1.31 $ & $ -170.67 \pm 1.14 $ & & ... & ... \\
11  & 70.35 & 69.82 & 0.52 & 0.23 & &$   56.12 \pm 0.94 $ & $  114.09 \pm 1.10 $ & & $ +0.62  $ & $ +1.0 $ \\
12  & 67.19 & ...   & 0.46 & ...  & &$   45.90 \pm 0.66 $ & $  111.93 \pm 0.98 $ & & ... & ... \\
13  & 76.33 & 79.67 & 0.25 & 0.43 & &$ -223.40 \pm 1.45 $ & $   71.08 \pm 1.20 $ & & $ -3.41  $ & $ -5.8 $ \\
14  & ...   & 76.33 & ...  & 0.41 & &$  366.46 \pm 1.57 $ & $ -149.68 \pm 1.13 $ & & ... & ... \\
15  & 68.77 & ...   & 0.38 & ...  & &$   52.32 \pm 2.18 $ & $  113.99 \pm 1.27 $ & & ... & ... \\
16  & ...   & 63.50 & ...  & 0.31 & &$   32.32 \pm 1.56 $ & $  108.87 \pm 1.73 $ & & ... & ... \\
17  & 64.90 & ...   & 0.30 & ...  & &$   39.23 \pm 1.10 $ & $  111.08 \pm 1.12 $ & & ... & ... \\
18  & 70.18 & ...   & 0.25 & ...  & &$  192.37 \pm 1.33 $ & $  175.05 \pm 1.53 $ & & ... & ... \\
19  & 79.32 & 77.21 & 0.25 & 0.17 & &$ -321.93 \pm 0.90 $ & $  130.00 \pm 2.23 $ & & $ +2.11  $ & $ +3.6 $ \\
20  & 64.55 & 65.08 & 0.23 & 0.13 & &$   37.16 \pm 0.92 $ & $  108.63 \pm 1.33 $ & & $ -0.49  $ & $ -0.8 $ \\
21  & 66.84 & ...   & 0.22 & ...  & &$ -134.66 \pm 0.91 $ & $  147.73 \pm 1.29 $ & & ... & ... \\
22  & 62.62 & 62.79 & 0.16 & 0.20 & &$   26.50 \pm 1.98 $ & $  106.74 \pm 1.81 $ & & ... & ... \\
23  & 69.65 & 69.30 & 0.18 & 0.19 & &$   17.17 \pm 1.78 $ & $   18.23 \pm 2.17 $ & & ... & ... \\
24  & 60.68 & 60.51 & 0.12 & 0.14 & &$   20.64 \pm 1.70 $ & $   70.44 \pm 2.47 $ & & ... & ... \\
\hline \noalign{\smallskip}
\multicolumn{11}{c}{Reference Feature: Absolute position}\\
Feature & \multicolumn{4}{c}{RA(J2000)} & \multicolumn{4}{c}{ Dec(J2000) } & &  \\
        & \multicolumn{4}{c}{(h m s)}     & \multicolumn{4}{c}{(\degr $'$ $''$)}  & &  \\
\hline
1  &\multicolumn{4}{c}{18:34:40.28515 $\pm$ 0.00026}&\multicolumn{4}{c}{$-$09:00:38.3783 $\pm$ 0.0044} & &  \\
\hline
\end{tabular}
\tablefoot {For each identified feature, the label (given in Col.~1) increases with decreasing brightness. Columns~2(3) and~4(5) report the LSR velocity and brightness of the brightest spot for the right (left) circular polarization. Columns~6 and~7 give the position offset relative to the feature~\#1, in~the east and north directions, respectively. Columns~8 and~9 report the fit split of LSR velocity (RCP-LCP) between co-spatial circular polarization components and the inferred l.o.s. magnetic field strength, respectively. The absolute position of the reference feature~\#1 is reported at the bottom of the table. \\
\tablefoottext{a}{A magnetic field of 0.34~mG shifts the emission velocity of 1665~MHz OH~masers by 0.2~km~s$^{-1}$.}}
\end{table}