\begin{table}%t2
\caption{\label{wat_tab}\label{tab2}Parameters of VLBA 22.2~GHz water maser features.}
\small%\centering
\par
\begin{tabular}{ccrcrrcrrr}
\hline \hline\noalign{\smallskip}
Feature &  $V_{\rm LSR}$ & \multicolumn{1}{c}{$F_{\rm peak}$}  & & \multicolumn{1}{c}{$\Delta x$} & \multicolumn{1}{c}{$\Delta y$} &  & \multicolumn{1}{c}{$V_{x}$} & \multicolumn{1}{c}{$V_{y}$} & \multicolumn{1}{c}{$\Delta|V|/|V| $} \\
        &  (km s$^{-1}$) & \multicolumn{1}{c}{(Jy beam$^{-1}$)} &  & \multicolumn{1}{c}{(mas)} & \multicolumn{1}{c}{(mas)} &  & \multicolumn{1}{c}{(km s$^{-1}$)} & \multicolumn{1}{c}{(km s$^{-1}$)} &                  \\
\hline
1    & 65.48 & 65.49 (2)& & $ -106.46\pm 0.23 $ & $ 132.43\pm0.44 $ & & $ -17.4\pm6.9 $ & $  40.8\pm12.9$ & 27\% \\
2    & 64.85 & 40.19 (4)& & $ -110.94\pm 0.18 $ & $ 142.62\pm0.18 $ & &      ...        &      ...        & ...  \\
3    & 65.06 & 27.55 (3)& & $ -108.89\pm 0.12 $ & $ 139.37\pm0.17 $ & & $ -23.3\pm5.5 $ & $  42.8\pm7.8 $ & 15\% \\
4    & 60.93 & 22.98 (1)& & $          0      $ & $          0    $ & &       0        &        0         &      \\
5    & 60.09 & 15.89 (1)& & $  107.14\pm 0.10 $ & $ 109.94\pm0.19 $ & & $  -0.1\pm7.0 $ & $  39.7\pm13.3$ & 33\% \\
6    & 64.52 & 11.63 (1)& & $ -111.92\pm 0.12 $ & $ 143.40\pm0.11 $ & & $  -3.3\pm4.0 $ & $  19.7\pm4.4 $ & 22\% \\
7    & 64.42 &  4.24 (4)& & $ -107.50\pm 0.09 $ & $ 131.83\pm0.11 $ & & $ -10.6\pm5.7 $ & $  43.1\pm6.6 $ & 15\% \\
8    & 61.48 &  3.30 (4)& & $  230.00\pm 0.10 $ & $ 685.88\pm0.18 $ & & $  -7.2\pm7.0 $ & $  35.4\pm11.7$ & 32\% \\
9    & 51.36 &  2.70 (4)& & $  256.26\pm 0.16 $ & $ 695.78\pm0.17 $ & & $  -1.8\pm8.5 $ & $  55.3\pm8.1 $ & 15\% \\
10   & 59.25 &  2.56 (1)& & $  229.96\pm 0.13 $ & $ 685.76\pm0.20 $ & &      ...        &      ...        & ...  \\
11   & 62.62 &  1.72 (1)& & $ -111.69\pm 0.09 $ & $ 120.16\pm0.10 $ & &      ...        &      ...        & ...  \\
12   & 64.42 &  1.70 (4)& & $ -105.56\pm 0.08 $ & $ 137.21\pm0.10 $ & &      ...        &      ...        & ...  \\
13   & 66.11 &  1.67 (3)& & $ -116.31\pm 0.09 $ & $ 156.20\pm0.10 $ & & $ -10.9\pm6.0 $ & $  43.5\pm8.5 $ & 19\% \\
14   & 60.84 &  1.48 (3)& & $  235.32\pm 0.08 $ & $ 673.64\pm0.10 $ & & $ -11.8\pm5.4 $ & $  19.7\pm6.1 $ & 26\% \\
15   & 61.26 &  1.31 (2)& & $  107.55\pm 0.07 $ & $ 111.31\pm0.09 $ & &      ...        &      ...        & ...  \\
16   & 60.63 &  1.11 (3)& & $    0.56\pm 0.14 $ & $  -1.27\pm0.13 $ & &      ...        &      ...        & ...  \\
17   & 66.74 &  0.87 (4)& & $ -115.99\pm 0.09 $ & $ 153.86\pm0.21 $ & &      ...        &      ...        & ...  \\
18   & 65.06 &  0.80 (3)& & $ -118.02\pm 0.11 $ & $ 153.03\pm0.18 $ & &      ...        &      ...        & ...  \\
19   & 61.90 &  0.79 (4)& & $ -108.63\pm 0.13 $ & $ 131.99\pm0.17 $ & &      ...        &      ...        & ...  \\
20   & 66.42 &  0.72 (1)& & $ -106.92\pm 0.10 $ & $ 129.23\pm0.18 $ & &      ...        &      ...        & ...  \\
21   & 65.48 &  0.71 (4)& & $  106.92\pm 0.08 $ & $ 110.26\pm0.09 $ & &      ...        &      ...        & ...  \\
22   & 59.58 &  0.64 (4)& & $  152.99\pm 0.09 $ & $   1.63\pm0.10 $ & & $   9.3\pm3.5 $ & $  11.7\pm4.2 $ & 27\% \\
23   & 67.89 &  0.57 (1)& & $ -115.27\pm 0.09 $ & $ 146.15\pm0.09 $ & &      ...        &      ...        & ...  \\
24   & 62.53 &  0.51 (4)& & $ -112.30\pm 0.08 $ & $ 126.55\pm0.09 $ & &      ...        &      ...        & ...  \\
25   & 66.74 &  0.49 (2)& & $ -115.84\pm 0.08 $ & $ 157.32\pm0.12 $ & & $ -27.4\pm5.0 $ & $ 113.8\pm7.6 $ &  6\% \\
26   & 64.10 &  0.46 (1)& & $ -106.47\pm 0.10 $ & $ 137.54\pm0.12 $ & &      ...        &      ...        & ...  \\
27   & 66.32 &  0.45 (3)& & $ -117.63\pm 0.08 $ & $ 162.42\pm0.12 $ & &      ...        &      ...        & ...  \\
28   & 65.48 &  0.40 (2)& & $  107.06\pm 0.09 $ & $ 109.40\pm0.10 $ & &      ...        &      ...        & ...  \\
29   & 62.74 &  0.39 (3)& & $ -112.00\pm 0.09 $ & $ 118.35\pm0.14 $ & &      ...        &      ...        & ...  \\
30   & 60.30 &  0.35 (1)& & $    6.92\pm 0.09 $ & $  12.23\pm0.12 $ & & $   4.9\pm3.6 $ & $  20.4\pm4.6 $ & 21\% \\
31   & 60.63 &  0.34 (4)& & $  107.16\pm 0.11 $ & $ 111.54\pm0.18 $ & &      ...        &      ...        & ...  \\
32   & 62.20 &  0.33 (1)& & $ -109.48\pm 0.19 $ & $ 128.05\pm0.20 $ & &      ...        &      ...        & ...  \\
33   & 60.84 &  0.25 (4)& & $    5.81\pm 0.09 $ & $  10.10\pm0.14 $ & &      ...        &      ...        & ...  \\
34   & 60.84 &  0.21 (3)& & $   -8.41\pm 0.09 $ & $  13.03\pm0.20 $ & &      ...        &      ...        & ...  \\
35   & 62.32 &  0.21 (4)& & $ -111.81\pm 0.08 $ & $ 120.87\pm0.12 $ & &      ...        &      ...        & ...  \\
36   & 63.46 &  0.18 (1)& & $ -107.52\pm 0.10 $ & $ 131.67\pm0.13 $ & &      ...        &      ...        & ...  \\
37   & 60.09 &  0.16 (1)& & $  106.91\pm 0.10 $ & $ 119.47\pm0.15 $ & &      ...        &      ...        & ...  \\
38   & 58.61 &  0.10 (1)& & $  228.34\pm 0.10 $ & $ -31.43\pm0.18 $ & & $  12.8\pm4.3 $ & $  10.4\pm7.0 $ & 34\% \\
39   & 63.04 &  0.10 (1)& & $  264.41\pm 0.11 $ & $ 684.83\pm0.15 $ & &      ...        &      ...        & ...  \\
40   & 60.00 &  0.10 (3)& & $  108.53\pm 0.09 $ & $ 113.03\pm0.15 $ & &      ...        &      ...        & ...  \\
\hline
\multicolumn{10}{c}{Reference Feature: Absolute position}\\
\hline \noalign{\smallskip}
Feature & \multicolumn{4}{c}{RA(J2000)} & \multicolumn{4}{c}{ Dec(J2000) }   &   \\
        & \multicolumn{4}{c}{(h m s)}     & \multicolumn{4}{c}{(\degr $'$ $''$)}    &   \\
\hline\noalign{\smallskip}
4 &\multicolumn{4}{c}{18:21:09.09211~$\pm$~0.00009}&\multicolumn{4}{c}{$-$14:31.48.6790~$\pm$~0.0023} & \\
\hline
\end{tabular}
\tablefoot{For each identified feature, the label (given in Col.~1) increases with decreasing brightness.
Columns~2 and~3 report the LSR velocity and brightness of the brightest spot (for the epoch specified by the number in brackets).
Columns~4 and~5 give the position offset relative to the feature~\#~4, in the east and north directions, respectively.
Columns~6 and~7 report the projected components of the feature proper motion relative the the feature~\#~4, along the east and north directions, respectively. Column~8 shows the relative error of the proper motion amplitude.
The absolute position of the reference feature~\#~4 is reported at the bottom of the table.}
\end{table}