\begin{table}
%\centering
\par
\caption{Radial velocities of the candidate binary systems identified in the
$\sigma$ Ori cluster sample.}\label{tab:vr_bin_sori} 
\small \begin{tabular}{ccccccc}
\hline \hline
 & \multicolumn{6}{c}{JD-2453000.00}\\
 & 280.82 & 341.73 & 342.73 & 343.82 & 344.71 & 349.71\\                   
\hline\noalign{\smallskip}
ID & RV (km~s$^{-1}$) & RV (km~s$^{-1}$)  & RV (km~s$^{-1}$)  & RV (km~s$^{-1}$)  & RV (km~s$^{-1}$)  & RV (km~s$^{-1}$) \\                   
 \hline
  S04 & $17.83\pm4.81$ & $33.10\pm3.01$ & $34.19\pm6.17$ & $32.21 \pm   4.64$ & $27.55\pm6.40$ & $34.94\pm4.57$ \\  
 S26 & $27.95\pm3.38$ & $43.72\pm2.90$ & $43.07\pm3.35$ & $44.88\pm  3.34$ & $45.25\pm3.18$ & $44.32\pm4.01$ \\  
 S29a & $6.56\pm4.03$ & $1.51\pm3.13$ & 
 $30.97\pm1.82$ & $60.81\pm3.99$ &
 $73.99\pm3.96$ & $-5.13\pm3.42$ \\  
S29b & $46.91\pm2.40$ & $49.93\pm2.41$ & 
 $30.97\pm1.82$ & $15.51\pm 2.11$&
 $7.20\pm2.18$ & $57.42\pm2.32$  \\  
 S43 & $39.17\pm1.41$ & $21.10\pm1.59$ & $18.60\pm1.67$ & $20.96 \pm  1.53$ & $20.13\pm1.62$ & $22.40\pm1.30$ \\  
 S50 & $11.81\pm1.13$ & $4.43\pm1.09$ & $2.95\pm1.34$ & $5.41 \pm   1.12$ & $4.77\pm1.69$ & $6.18\pm1.21$ \\  
S53a & $31.50\pm2.03$ & $55.34\pm3.59$& 
 $55.84\pm3.90$& $51.82\pm3.58$ &
 $29.51\pm2.34$ & $45.68\pm2.44$  \\  
S53b & $31.50\pm2.03$ & $4.24\pm2.52$ & 
 $1.14\pm2.97$ & $9.07\pm2.82$ &
 $29.51\pm2.34$ & $12.21\pm3.82$  \\  
S84a & $69.90\pm2.24$ & $68.11\pm2.64$ & 
$21.78\pm2.06$ & --$7.34\pm2.29$ &
 --$25.03\pm3.06$& --$1.15\pm2.50$  \\  
S84b & --$22.45\pm2.53$ & --$19.67\pm2.75$ & 
$21.78\pm2.06$& $54.91\pm2.20$ &
 $71.85\pm2.51$ & $47.48\pm2.47$  \\  
S85a & $73.12\pm2.15$& $31.13\pm3.29$ & 
$34.13\pm3.68$ & $59.05\pm5.85$ &
 $72.54\pm2.28$ & $101.53\pm3.80$  \\  
 S85b & $73.12\pm2.15$ & $106.96\pm3.39$ & 
$99.75\pm2.87$ & $87.84\pm3.10$ &
 $72.54\pm2.28$ & $45.87\pm3.13$  \\  
S89a & $52.14\pm8.76$ & $27.99\pm5.64$ & 
--$25.75 \pm 8.10$ & --$48.08\pm4.31$ &
--$65.28\pm6.26$ & $59.86\pm7.67$  \\  
S89b & --$20.04 \pm 5.23$ & $10.07\pm7.17$ & 
$43.42\pm5.42$& $66.46\pm4.08$ &
$85.63\pm4.75$ & --$10.17 \pm 7.02$  \\  
S91 & $75.36\pm1.44$ & $81.10\pm2.27$ & $81.19\pm1.91$ & $83.45 \pm 1.61$ & $83.22\pm1.91$ & $84.46\pm1.62$ \\  
S96 & --$7.70\pm2.77$ & --$27.13 \pm 2.98$ & $7.54 \pm 2.12$ & --$52.30 \pm
2.54$ & --$76.51 \pm 2.62$ & --$13.99 \pm 2.95$ \\  
\hline
 \end{tabular}
\end{table}