\begin{table}%t2
\caption{\label{tab2}Sources parameters.}
\par
\small%\centerline
 {
\begin{tabular}{lrc|lrc|lrc}
\hline          
\hline
\s MSX6C Name &\s $\alpha$ &\s $EM$                    &\s MSX6C Name &\s $\alpha$ &\s $EM$                    &\s MSX6C Name &\s $\alpha$ &\s $EM$                    \\
        &      &\s $\times 10 ^7$ [pc cm$^{-6}$] &        &      &\s $\times 10 ^7$ [pc cm$^{-6}$] &        &      &\s $\times 10 ^7$ [pc cm$^{-6}$] \\
\hline
&&&&&&&& \\[-8pt]
\s$17.2231+0.3952^{\dag}$ &\s$0.54$  &\s${>}3.12~~~~$   &\s$26.0905-0.0578$        &\s$0.11$  &\s$0.11$   &\s$31.0702+0.0498$        &\s$0.34$  &\s$0.19$  \\
\s$16.9440-0.0736$        &\s$0.23$  &\s$6.17 $   &\s$26.6085-0.2122$        &\s$-0.09$ &\s$0.26$   &\s$31.2803+0.0615$        &\s$0.01$  &\s$0.21$  \\
\s$18.4608-0.0034$        &\s$0.02$  &\s$3.39 $   &\s$27.4938+0.1893$        &\s$0.31$  &\s$0.03$   &\s$30.6671-0.3316$        &\s$0.13$  &\s$4.77$  \\
\s$18.7104+0.0001^{\dag}$ &\s$0.45$  &\s${>}12.80~~~~~~$  &\s$27.9777+0.0780$        &\s$0.27$  &\s$0.11$   &\s$31.2430-0.1108$        &\s$0.16$  &\s$1.12$  \\
\s$18.3029-0.3910$        &\s$-0.13$ &\s$0.11 $   &\s$28.2461+0.0134$        &\s$0.24$  &\s$0.10$   &\s$32.1514+0.1317$        &\s$-0.14$ &\s$0.06$  \\
\s$18.7084-0.1263$        &\s$-0.03$ &\s$3.76 $   &\s$28.2007-0.0494^{\dag}$ &\s$0.58$  &\s${>}2.21~~~~$  &\s$31.3948-0.2585$        &\s$0.53$  &\s$0.13$  \\
\s$19.7403+0.2799$        &\s$0.07$  &\s$0.03 $   &\s$28.6096+0.0170$        &\s$0.21$  &\s$3.25$   &\s$32.4727+0.2041$        &\s$0.34$  &\s$3.12$  \\
\s$18.8330-0.3004$        &\s$0.41$  &\s$0.50 $   &\s$28.6520+0.0271$        &\s$0.09$  &\s$0.61$   &\s$32.7977+0.1903^{\dag}$ &\s$0.31$  &\s${>}3.41~~~~$ \\
\s$21.8732+0.0076$        &\s$-0.03$ &\s$0.13 $   &\s$28.2875-0.3639$        &\s$-0.06$ &\s$1.89$   &\s$32.2718-0.2260$        &\s$-0.15$ &\s$0.25$  \\
\s$21.3853-0.2537^{\dag}$ &\s$0.32$  &\s${>}2.49~~~~$   &\s$29.2113-0.0690$        &\s$0.08$  &\s$0.73$   &\s$33.8104-0.1869$        &\s$0.32$  &\s$0.03$  \\
\s$22.7253-0.0106$        &\s$0.28$  &\s$0.07 $   &\s$29.9564-0.0174$        &\s$0.09$  &\s$3.00$   &\s$35.4672+0.1381$        &\s$0.04$  &\s$0.76$  \\
\s$23.9548+0.1494$        &\s$-0.10$ &\s$0.12 $   &\s$30.5345+0.0209$        &\s$0.08$  &\s$1.24$   &\s$35.5736+0.0678$        &\s$0.19$  &\s$0.26$  \\
\s$24.5076-0.2222^{\dag}$ &\s$0.35$  &\s${>}0.76~~~~$   &\s$30.2340-0.1392$        &\s$-0.15$ &\s$3.16$   &\s$35.5789-0.0304^{\dag}$ &\s$0.62$  &\s${>}8.96~~~~$  \\
\s$25.5196+0.2156$        &\s$0.04$  &\s$0.29 $   &\s$30.8667+0.1141$        &\s$0.34$  &\s$5.38$   &\s$38.5497+0.1636$        &\s$0.03$  &\s$0.03$  \\
\s$25.2666-0.1584$        &\s$-0.09$ &\s$10.71~$   &\s$31.4134+0.3092$        &\s$-0.13$ &\s$0.56$   &\s$38.8750+0.3088$        &\s$0.08$  &\s$2.25$  \\
\s$25.3977-0.1406$        &\s$0.00$  &\s$0.60 $   &\s$30.6877-0.0729$        &\s$0.06$  &\s$1.72$   &\s$39.8821-0.3457$        &\s$-0.07$ &\s$1.75$  \\
\s$25.3820-0.1813$        &\s$0.29$  &\s$0.80 $   &\s$30.7206-0.0826$        &\s$0.11$  &\s$3.76$   &\s$41.7410+0.0972$        &\s$-0.09$ &\s$0.08$  \\
\hline                            
\end{tabular}}                                                        
\medskip
$^{\dag}$ For these sources the simulated radio spectra indicate that the emission is optically thick up to 7~mm, the derived $EM$ has to be considered as a lower limit.
\vspace*{3mm}
\end{table}