\begin{table}%t1
%\centering
\par
\caption{\label{tab:hdw}Definition of the H$\delta_{{\rm W}}$ index.}
\small \begin{tabular}{cc}
\hline \hline\noalign{\smallskip}
Bandpass & $\lambda$ (\AA)\\
\hline
central & $\left[4060.5;4145\right]$\\
blue & $\left[4014;4054\right]$\\
red & $\left[4151;4191\right]$\\
\hline
\end{tabular}
\end{table}