\begin{table}%ta1 \caption{\label{TabFitHCOp}HCO$^{+}$ (0--1) absorption line analysis results.} %\centerline {\small \begin{tabular}{l c c c c c} \hline\hline \tablefootmark{a}& $\upsilon_0$ & $\Delta \upsilon$ & $\tau_0$ & $N$(HCO$^{+}$) &$N_{\rm H}$ \\ Source & (\kms) & (\kms) & & ($10^{12}$ cm$^{-2}$)&($10^{20}$ cm$^{-2}$) \\ \hline {\bf G05.88-0.39} & $-4.92$ &1.13 $\pm$ 0.15& 0.09 $\pm$ 0.01 & 0.13 $\pm$ 0.03 & \\ \\[-1mm] {\bf G08.67-0.36} & 9.82 &0.95 $\pm$ 0.12& 1.60 $\pm$ 0.28 & 2.02 $\pm$ 0.58 & \\ & 11.71 &1.40 $\pm$ 0.17& 1.65 $\pm$ 0.28 & 3.08 $\pm$ 0.90 & \\ & 14.52 &2.00 $\pm$ 0.18& 1.41 $\pm$ 0.18 & 3.74 $\pm$ 0.83 & \\ & 17.76 &1.17 $\pm$ 0.22& 0.87 $\pm$ 0.20 & 1.34 $\pm$ 0.56 & \\ & 20.00 &2.55 $\pm$ 0.63& 1.08 $\pm$ 0.16 & 3.65 $\pm$ 1.45 & \\ & 22.00 &1.02 $\pm$ 0.58& 0.24 $\pm$ 0.17 & 0.32 $\pm$ 0.41 & \\ \\[-1mm] {\bf G10.62-0.38} & 11.62 &1.10 $\pm$ 0.12& 0.43 $\pm$ 0.04 & 0.62 $\pm$ 0.12 & \\ & 16.38 &2.35 $\pm$ 0.10& 2.23 $\pm$ 0.14 & 6.84 $\pm$ 0.74 & \\ & 19.00 &2.13 $\pm$ 0.20& 1.50 $\pm$ 0.09 & 4.18 $\pm$ 0.64 & \\ & 22.20 &2.70 $\pm$ 0.27& 1.57 $\pm$ 0.13 & 5.57 $\pm$ 1.00 & \\ & 22.95 &1.15 $\pm$ 0.45& 0.82 $\pm$ 0.18 & 1.23 $\pm$ 0.75 & \\ & 24.98 &1.65 $\pm$ 0.10& 0.70 $\pm$ 0.06 & 1.51 $\pm$ 0.21 & \\ & 27.50 &2.58 $\pm$ 0.17& 1.61 $\pm$ 0.11 & 5.46 $\pm$ 0.74 & \\ & 29.00 &1.53 $\pm$ 0.52& 0.78 $\pm$ 0.20 & 1.56 $\pm$ 0.93 & \\ & 30.50 &1.52 $\pm$ 0.32& 2.09 $\pm$ 0.27 & 4.13 $\pm$ 1.39 & \\ & 40.91 &2.60 $\pm$ 0.10& 2.33 $\pm$ 0.14 & 7.93 $\pm$ 0.78 & \\ & 44.94 &1.22 $\pm$ 0.05& 1.30 $\pm$ 0.07 & 2.06 $\pm$ 0.21 & \\ & 46.40 &0.60 $\pm$ 0.10& 0.26 $\pm$ 0.04 & 0.20 $\pm$ 0.07 & \\ \\[-1mm] {\bf G34.3+0.1} & 9.80 &0.53 $\pm$ 0.22& 0.38 $\pm$ 0.12 & 0.27 $\pm$ 0.19 & \\ & 10.60 &0.57 $\pm$ 0.12& 1.86 $\pm$ 0.61 & 1.38 $\pm$ 0.72 & \\ & 11.70 &1.37 $\pm$ 0.18& 1.82 $\pm$ 0.39 & 3.34 $\pm$ 1.14 & \\ & 14.07 &0.37 $\pm$ 0.08& 0.77 $\pm$ 0.23 & 0.38 $\pm$ 0.20 & \\ & 27.00 &1.02 $\pm$ 0.13& 1.19 $\pm$ 0.20 & 1.61 $\pm$ 0.47 & \\ & 27.75 &1.83 $\pm$ 0.32& 0.45 $\pm$ 0.09 & 1.10 $\pm$ 0.41 & \\ & 48.30 &2.23 $\pm$ 0.20& 0.94 $\pm$ 0.10 & 2.80 $\pm$ 0.54 & \\ \\[-1mm] {\bf W49N} & 33.20 &0.65 $\pm$ 0.03& 0.44 $\pm$ 0.02 & 0.34 $\pm$ 0.02 & 3.0 \\ & 33.70 &2.23 $\pm$ 0.03& 0.63 $\pm$ 0.01 & 1.67 $\pm$ 0.02 & 10.5 \\ & 36.50 &1.67 $\pm$ 0.12& 0.29 $\pm$ 0.01 & 0.60 $\pm$ 0.03 & 7.8 \\ & 38.50 &1.75 $\pm$ 0.08& 0.91 $\pm$ 0.01 & 1.88 $\pm$ 0.03 & 8.2 \\ & 39.70 &1.47 $\pm$ 0.02& 2.01 $\pm$ 0.03 & 3.47 $\pm$ 0.05 & 6.9 \\ & 50.92 &1.65 $\pm$ 0.10& 0.35 $\pm$ 0.01 & 0.68 $\pm$ 0.02 & 7.8 \\ & 53.40 &1.23 $\pm$ 0.10& 0.30 $\pm$ 0.02 & 0.43 $\pm$ 0.03 & 5.8 \\ & 54.00 &3.38 $\pm$ 0.15& 0.51 $\pm$ 0.01 & 2.03 $\pm$ 0.04 & 15.9 \\ & 56.70 &2.35 $\pm$ 0.07& 0.69 $\pm$ 0.01 & 1.91 $\pm$ 0.03 & 11.0 \\ & 59.55 &2.35 $\pm$ 0.05& 1.89 $\pm$ 0.02 & 5.24 $\pm$ 0.07 & 11.0 \\ & 60.80 &0.88 $\pm$ 0.05& 0.77 $\pm$ 0.05 & 0.80 $\pm$ 0.06 & 4.1 \\ & 62.65 &2.95 $\pm$ 0.03& 1.48 $\pm$ 0.01 & 5.16 $\pm$ 0.05 & 13.9 \\ & 66.21 &1.85 $\pm$ 0.07& 0.19 $\pm$ 0.01 & 0.41 $\pm$ 0.01 & 8.7 \\ & 68.58 &1.80 $\pm$ 0.10& 0.24 $\pm$ 0.01 & 0.52 $\pm$ 0.01 & 8.5 \\ & 71.11 &2.25 $\pm$ 0.20& 0.07 $\pm$ 0.00 & 0.19 $\pm$ 0.01 & 10.6 \\ \\[-1mm] {\bf W51} & 3.80 &0.47 $\pm$ 0.12& 0.10 $\pm$ 0.02 & 0.06 $\pm$ 0.03 & 1.0 \\ & 5.10 &1.23 $\pm$ 0.05& 0.72 $\pm$ 0.02 & 1.14 $\pm$ 0.08 & 2.7 \\ & 6.25 &0.65 $\pm$ 0.03& 1.05 $\pm$ 0.06 & 0.87 $\pm$ 0.10 & 1.4 \\ & 6.85 &2.01 $\pm$ 0.05& 0.70 $\pm$ 0.02 & 1.80 $\pm$ 0.10 & 4.4 \\ & 12.71 &1.67 $\pm$ 0.18& 0.10 $\pm$ 0.01 & 0.20 $\pm$ 0.04 & 3.7 \\ \hline \noalign{\smallskip} \tablefootmark{b} & $\upsilon_{\rm min}$ & $\upsilon_{\rm max}$ & $\int \tau {\rm d}\upsilon$ & $N$(HCO$^{+}$) & \\ Source & (\kms) & (\kms) & (\kms) & ($10^{12}$ cm$^{-2}$) & \\ \hline {\bf G10.62-0.38} & 13.6 & 15.2 & 0.77 $\pm$ 0.08 & 0.94 $\pm$ 0.10 & \\ & 31.0 & 33.0 & 3.77 $\pm$ 0.31 & 4.63 $\pm$ 0.38 & \\ & 33.3 & 34.7 & 1.81 $\pm$ 0.15 & 2.23 $\pm$ 0.18 & \\ & 34.7 & 36.0 & 1.74 $\pm$ 0.16 & 2.13 $\pm$ 0.19 & \\ & 36.0 & 37.5 & 3.10 $\pm$ 0.29 & 3.82 $\pm$ 0.36 & \\ & 37.5 & 40.0 & $>$6.27 & $>$7.71 & \\ \\ {\bf W49N} & 41.0 & 47.0 & 0.90 $\pm$ 0.03 & 1.00 $\pm$ 0.04 & \\ \hline \end{tabular}} \tablefoot{\tablefoottext{a}{Multi-Gaussian decomposition. The column densities are derived assuming the excitation temperatures given in Table \ref{TabTex}.} \tablefoottext{b}{Failure of the multi-gaussian decomposition. Column densities are inferred from the integral of the opacity assuming the excitation temperatures given in Table \ref{TabTex}.} \tablefoottext{c}{Determined from the average total hydrogen column density per unit velocity $N_{\rm H}/\Delta v = 2.2$ and 4.7$\times 10^{20}$ cm$^{-2}$/km s$^{-1}$ toward W51 and W49N respectively.}} \end{table}