\begin{table}%t3
\caption{SIDAM analysis: optimized centroid positions of the \ion{Fe}{ii}~lines in the main subcomponent and~$\Delta\alpha/\alpha$ calculated with Eqs.~(\ref{eq:A4}) or~(\ref{eq:A10}).}
\label{tbl-3}
%\centering
\par
\begin{tabular}{ccccccc}
\hline
\hline
Exp.  & $\lambda_{\rm obs}$, \AA & $\lambda_{\rm obs}$, \AA &
$\lambda_{\rm obs}$, \AA & $\lambda_{\rm obs}$, \AA & 
\multicolumn{1}{c}{$(\Delta\alpha/\alpha)$}& pair, \\
No. & $\lambda1608$ & $\lambda2382$ & $\lambda2586$ & $\lambda2600$ & 
\multicolumn{1}{c}{(in units of $10^{-5}$)} & $\lambda_1/\lambda_2$ \\
(1) & (2) & (3) & (4) & (5) & \multicolumn{1}{c}{(6)} & (7) \\
\hline
11/12 & 4566.24408 & 6764.43913 & 7343.27915 & 7381.65008 & 1.199 & 1608/2382\\
      &  &  &  &  &  \hspace{-0.15cm}--2.103 & 1608/2586\\
      &  &  &  &  & 0.098 & 1608/2600 \\
19/20 & 4566.23755 & 6764.44738 & 7343.26356 & 7381.64359& 
\hspace{-0.15cm}--1.047 &1608/2382 \\
      & & & & & \hspace{-0.15cm}--1.525& 1608/2586 \\
      & & & & &  \hspace{-0.15cm}--0.393& 1608/2600 \\
21/22 & 4566.24661 & 6764.43913 & 7343.25994 & 7381.63961&1.668& 1608/2382\\
      & & & & & 0.539& 1608/2586\\
      & & & & & 1.860& 1608/2600  \\
23/24 & 4566.25102 & 6764.44933 & 7343.27203 & 7381.65019&1.209& 1608/2382 \\
      & & & & &  \hspace{-0.15cm}--0.028 &  1608/2586 \\
      & & & & & 1.442 &  1608/2600 \\
\multicolumn{5}{r}{sample mean $\langle \Delta\alpha/\alpha\rangle$:} & 
\multicolumn{1}{c}{0.24} &  \\
\multicolumn{5}{r}{error of the mean $\sigma/\sqrt{n}$:} & 
\multicolumn{1}{c}{0.38} & \\
\hline
\end{tabular}
\end{table}