\begin{table}%t3
%\centering
\par
\caption{\label{DUSTY_input}Range of the input parameters to DUSTY covered in the present study.}
\begin{tabular}{lll}
\hline \hline \noalign{\smallskip}
Parameter   & Range   & Step \\
\hline
$\alpha$    & 0.2--2.5  &  0.1    \\ 
$Y$           & 50--2000   & 10  \\ 
$\tau_{100}$ & 0.1--10.  & 0.1 \\
$T_{\rm  in}$     & 300 K    & \\
$T_*$       & 5000~K    & \\
\hline 
\end{tabular}
\tablefoot{The range of the $\alpha$, $Y$ and $\tau_{100}$ parameters are
  covered by increasing by a constant value at each step of the grid
  reported in the third column. Note that $T_{\rm  in}$ and $T_{_*}$ remain
   fixed as they do not influence the results (see
  text).}
\end{table}