\begin{table}%t2
\caption{Line parameters used for the fitting procedure in the first spectral region (3865.9--3866.8~\AA). The columns list the wavelength ($\lambda$), the line identification (ID), the polarizability ($W_2$), the lifetime of the upper level ($\tau_R$), the turbulent magnetic field strength at which the line polarization is reduced to 30\% of its non-magnetic value neglecting elastic collision ($B_{30}$), the vibrational number which coincides for the upper and lower states ($v$), and the oscillator strength ($f_{vJS}$). } % title of Table
\label{table:region1}
% is used to refer this table in the text
%\centering
 % used for centering table
\begin{tabular}{ c  c  c c  c  c c | c  c  c c  c  c c} % centered columns (4 columns)
\hline
\hline
 $\lambda$, \AA\  &  ~~~ID     & $W_2$ &   $\tau_R$,  $10^{-8}$~s & $B_{30}$  & $v$  & $f_{vJS}$ &  $\lambda$, \AA\  &  ~~~ID     & $W_2$ &   $\tau_R$,  $10^{-8}$~s & $B_{30}$  & $v$  & $f_{vJS}$ \\  % table heading
 \hline
3865.978&$   R_{1}(12)$&   0.1239&   7.2719&    22&   0&      0.391&3865.998&$   R_{2}(12)$&   0.1260&   7.2736&    22&   0&      0.362\\
3866.013&$   Q_{12}(12)$&   0.3982&   7.2736&    22&   0&      0.001&3866.096&$   P_{1}( 6)$&   0.0604&   7.4397&     9&   1&      0.154\\
3866.090&$   Q_{21}( 6)$&   0.3916&   7.4397&     9&   1&      0.002&3866.098&$   P_{2}( 6)$&   0.0545&   7.4635&     9&   1&      0.130\\
3866.160&$   P_{1}(69)$&   0.0957&   7.0063&   111&   0&      2.016&3866.086&$   Q_{21}(69)$&   0.3999&   7.0063&   111&   0&      0.000\\
3866.235&$   P_{2}(69)$&   0.0957&   7.0069&   111&   0&      1.987&3866.400&$   P_{1}(52)$&   0.0944&   7.2450&    86&   1&      1.254\\
3866.344&$   Q_{21}(52)$&   0.3999&   7.2450&    86&   1&      0.000&3866.460&$   P_{2}(52)$&   0.0943&   7.2456&    86&   1&      1.230\\
3866.540&$   P_{1}( 7)$&   0.0650&   7.4251&    11&   1&      0.178&3866.533&$   Q_{21}( 7)$&   0.3938&   7.4251&    11&   1&      0.002\\
\hline
\end{tabular}
\end{table}