\begin{table}%t2
\caption{Estimates of the uncertainties in the velocity dispersion due to changes in aperture dimensions for the central and most intense Gaussian function fitted to the observed spectrum for a group of selected \hii~regions in the barred galaxies: NGC~3359, NGC~1530 and NGC~6951. The catalogued radii of the \hii~regions (Rad. in Col.~3) and the apertures are in pixels in the intensity maps and~$\sigma$ in~\kms. The third value for~$\sigma$ is obtained with a circular aperture of radius~$r$. This radius~$r$ is the mean value of the radii obtained from the rectangular
apertures, assuming their areas are equal to those of circular projected areas.}\label{taberrsigma}
%\centering
\par
\begin{tabular}{ccc|cc|cc|cc}
\hline
\hline
Region & log~$L_{\scriptsize\ha}$ & Rad. & $\sigma$ & Aperture & $\sigma$ & Aperture & $\sigma$ & $r$ \\
(galaxy) & (\ergs) & (pix) & (\kms) & (pix $\times$ pix) & (\kms) & (pix $\times$ pix) & (\kms) & (pix) \\
\hline
11(N1530)  & 39.4338 & 6.0 &  39.5 $\pm$ 5.0 &15 $\times$ 8 & 38.6 $\pm$ 4.0 & 7 $\times$ 5 &
41.5 $\pm$ 4.3 & 4.8 \\
15(N1530)  & 39.3467 & 5.9 &  40.7 $\pm$ 0.7 & 7 $\times$ 7 & 41.0 $\pm$ 0.6 & 6 $\times$ 4 &
40.4 $\pm$ 0.6 & 3.4 \\
35(N1530)  & 38.8842 & 3.8 &  35.3 $\pm$ 5.1 & 7 $\times$ 8 & 34.6 $\pm$ 3.3 & 6 $\times$ 4 &
38.8 $\pm$ 3.8 & 3.5 \\
63(N3359)  & 38.4188 & 5.9 &  26.0 $\pm$ 0.9 & 7 $\times$ 5 & 25.2 $\pm$ 0.8 & 4 $\times$ 5 &
25.4 $\pm$ 0.8 & 3.3 \\
51(N3359)  & 38.5170 & 5.1 &  27.1 $\pm$ 0.8 & 8 $\times$ 6 & 25.6 $\pm$ 0.8 & 6 $\times$ 5 &
26.7 $\pm$ 0.9 & 3.5 \\
41(N3359)  & 38.5965 & 6.1 &  28.4 $\pm$ 0.5 & 8 $\times$ 11 & 28.3 $\pm$ 0.5 & 7 $\times$ 6 &
28.7 $\pm$ 0.5 & 4.5 \\
21(N6951)  & 38.5823 & 2.9 &  31.0 $\pm$ 0.8 & 7 $\times$ 8 & 31.1 $\pm$ 0.7 & 5 $\times$ 5 &
31.2 $\pm$ 0.6 & 3.5 \\
28(N6951)  & 38.4441 & 2.6 &  24.8 $\pm$ 0.8 & 8 $\times$ 6 & 24.7 $\pm$ 0.7 & 4 $\times$ 5 &
24.8 $\pm$ 0.6 & 3.2 \\
3(N6951)   & 39.1203 & 4.4 &  29.1 $\pm$ 0.5 & 7 $\times$ 8 & 28.7 $\pm$ 0.5 & 6 $\times$ 5 &
28.9 $\pm$ 0.4 & 3.6 \\
\hline
\end{tabular}
\end{table}