\begin{table}%t5
%\centering
\par
\caption{Observed line fluxes ($W=\int T_{\rm MB}~ {\rm d}V$ in K~km~s$^{-1}$) and 
line widths ($\Delta V$ in km~s$^{-1}$) for the NO, CO$^+$ and SO$^+$ 
transitions. The frequencies are given in GHz. Upper limits are at $3\sigma$ in 
line flux. Numbers in brackets are uncertainties in units of the 
the last decimal place. The hyperfine line widths of NO were taken to be fixed with an estimated error of $\lesssim$30\%.}
%\centerline
{\begin{tabular}{lrrrrrrrrrrrr} \hline\hline
Source  & NO      & & & NO & & & CO$^+$ & & CO$^+$ & & SO$^+$ & \\ 
        & 351.043 & & & 351.051 & & & 353.741 & & 354.014 & & 347.740 & \\ 
        & $W$     & $\Delta V$ & $\tau$ & $W$ & $\Delta V$ & $\tau$ & $W$ & $\Delta V$ & $W$ & $\Delta V$ & $W$ & $\Delta V$ \\ \hline
AFGL 2591 & 0.99(6) & 4.1 & 0.28(2) & 1.30(6) & 4.1 & 0.21(1) & 0.50(6) & 4.0(6) & 0.27(3) & 4.0$^a$ & 0.40(3) & 5.1(5) \\
W3 IRS 5 & 1.79(5) & 4.7 & 0.37(9) & 2.21(5) & 4.7 & 0.30(7) & 0.82(4) & 3.6(5) & 0.37(4) & 3.6$^a$ & 3.59(10) & 4.5(6) \\
IRAS 16293 & ... & ... & ... & ... & ... & ... & 0.31(4) & 2.9$^a$ & 0.21(7) & 2.7(6) & $\lesssim$0.17 & ... \\
N1333-I2  & 0.10(2) & 0.9 & 0.01(1) & 0.10(2) & 0.9 & 0.01(1) & $\lesssim$0.09 & 1.9 & $<$0.05 & ... & $<$0.04 & ... \\
N1333-I4A & 0.13(2) & 0.9 & 0.01(1) & 0.24(2) & 1.5 & 0.01(1) & $<$0.06 & ... & $<$0.06 & ... & $<$0.04 & ... \\
L1448-C   & ... & ... & ... & ... & ... & ... & $<$0.05 & ... & $<$0.05 & ... & $<$0.04 & ... \\
L483      & ... & ... & ... & ... & ... & ... & $<$0.04 & ... & $<$0.04 & ... & ... & ... \\
L723      & ... & ... & ... & ... & ... & ... & $<$0.05 & ... & $<$0.05 & ... & $<$0.07 & ... \\
SMM4      & ... & ... & ... & ... & ... & ... & $<$0.05 & ... & $<$0.05 & ... & $<$0.07 & ... \\
V1057 Cyg & ... & ... & ... & ... & ... & ... & $<$0.05 & ... & $<$0.05 & ... & $<$0.07 & ... \\ \hline
\label{tobs3}
\end{tabular}}
\hspace{-9cm} $^a$ The line width was taken to be fixed due to the noisy spectrum.
\end{table}