**Table 5:** Relaxation time and evolutionary parameter.
$\begin{displaymath}{ \begin{tabular}{lr@{$~\pm~$}lr@{$~\pm~$}lcr@{$~\pm~$}lr@{$~... ...\\ NGC~188&14&9&504&321&&631&400&11&7\\ \hline \end{tabular}}\end{displaymath}$ Table Notes. The relaxation time is calculated according to $\mbox{$t_{{\rm relax}}$ }\approx0.12\left(\frac{N}{\ln N}\right)\left(\frac{R}{... ...rm pc}}\right)\left(\frac{\sigma_v} {1~{\rm km~s}^{-1}}\right)^{-1} ({\rm Myr})$ , where N is the total number of stars, R is the radius of the region considered and $\sigma_v$ is the velocity dispersion. We adopted $\sigma_v\approx3~\mbox{$\rm km~s^{-1}$ }$ (Binney & Merrifield 1998). $\tau={\rm age}/\mbox{$t_{{\rm relax}}$ }$ is the evolutionary parameter.

Source LaTeX | All tables | In the text