\begin{table}%t1
%\setlength\tabcolsep{4.5pt}
%\centering
\par
 \caption {\label{tab1}Models of SF assumed in the new library.}
 \small
 \begin{tabular}{c c}
 \hline\hline
  Galaxy type         & {\it SFR }           \\
 \hline
Early-type galaxies & $p_{2}\exp(-t/p_{1}$)/$p_{1}$                        \\
\par
Spiral galaxies     & $(M_{\rm gas}^{p_{1}})/p_{2}$                   \\
\par
Irregular galaxies  & $(M_{\rm gas}^{p_{1}})/p_{2}$                   \\
\par
Quenched star-forming galaxies & $(M_{\rm gas}^{p_{1}})/p_{2}$ for $t<t_{f}-p_{3}$ \\
                               & 0 for $t>t_{\rm f}-p_{3}$ where \\
                               & ($t_{\rm f}=9$~Gyr, the age of the galaxy) \\
\hline
\end{tabular}
\end{table}