\begin{table}%T1
      \caption{Main parameters of the Galaxy thin-disc model from Chen et~al.
      (\cite{Chen2001}).} 
         \label{parameters}
    \small%\centering
\par
         \begin{tabular}{l c c c c}
            \hline
            \hline
  Parameter  	& $R_\odot$ 	& $Z_\odot$ 	& $h_R$ 		& $h_Z$ \\
	  	& (pc)		& (pc)		& (pc)			& (pc) \\
              \hline
  Value    	& $8600 \pm 200$& $+27 \pm 4$   	& $2250 \pm 1000$	& $330 \pm 3$ \\
             \hline
         \end{tabular} 
   \end{table}