\begin{table}%t6
\caption{\label{tab9}\ion{H}{ii} region model parameters.}
\par
%\centerline
{\small
\begin{tabular}{l c c c}
\hline\hline
Spectral type & $M$ & Number & $N_{\ion{Ly}{\alpha}}$ \\
 &($M_\odot$)& (stars)& ($\rm 10^{48}~photon~s^{-1}$) \\
\hline
$O5$ & $30$ & $20 $ & $2.00  $ \\
     & $22$ & $41 $ & $0.25  $ \\
$B0$ & $17$ & $75 $ & $0.082 $ \\
     & $15$ & $101$ & $0.043 $ \\
     & $13$ & $142$ & $0.015 $ \\
     & $10$ & $264$ & $0.0021$ \\
\hline
\end{tabular}}
\par
\medskip
Notes.
Column~2: representative stellar mass; Col.~3: number of stars; Col.~3: number of ionising
photons.
\end{table}