\begin{table}%t3
%\centering
\par
\caption{\small Log of the five types of power spectrum 
        in the left branch. Grouped
        observations are indicated by "--'' symbols. \label{tab3}}
\begin{tabular}{l|l}
\hline
\hline
Type & Observations\\
No signal &65, 68, 72, 73, 76, 77--78, 83--84, 89--90, 100,\\
          &105--106\\
Red noise &56, 57--58, 60, 63--64, 70--71, 74--75, 86\\
Weak QPO  &44--46, 66--67, 69, 79, 82, 85, 88b, 91--92, 94, 96,\\
          &98--99, 101--102, 103b, 107\\
LF noise  &35, 36--40, 47--50, 51, 52--55, 59, 61--62, 80--81,\\
          &87, 88, 93, 95, 103, 104, 108, 109\\
type-B QPO&34, 41, 42, 43, 97\\
\hline
\end{tabular}
\end{table}