\begin{table}%t6 \caption{\label{dcop_result}Rotational analysis for HCO$^+$ and isotopologues. Upper limits are 3$\sigma$. } \small%\centerline { \begin{tabular}{lcccccc} \hline \hline & \multicolumn{3}{c}{clump~1} & \multicolumn{3}{c}{clump~3} \\ $T_{\rm rot}$ & $N_{\rm DCO^+}$ & $N_{\rm H^{13}CO^+}$ & $N_{\rm DCO^+}$/$N_{\rm HCO^+}$$^1$ & $N_{\rm DCO^+}$ & $N_{\rm H^{13}CO^+}$ & $N_{\rm DCO^+}$/$N_{\rm HCO^+}$$^1$ \\ & \small{(cm$^{-2}$)} & \small{(cm$^{-2}$)} & & \small{(cm$^{-2}$)} & \small{(cm$^{-2}$)} & \\ \hline \noalign{\smallskip} 20 K & $<$1.6~$\times$~10$^{11}$ & 1.0~$\times$~10$^{13}$ & $<$2.3~$\times$~10$^{-4}$ & (5.0~$\pm$~0.8)~$\times$~10$^{11}$ & (9.9~$\pm$~0.1)~$\times$~10$^{12}$ & (7.3~$\pm$~1.4)~$\times$~10$^{-4}$ \\ 30 K & $<$2.0~$\times$~10$^{11}$ & 1.4~$\times$~10$^{13}$ & $<$2.0~$\times$~10$^{-4}$ & (6.2~$\pm$~1.0)~$\times$~10$^{11}$ & (1.4~$\pm$~0.2)~$\times$~10$^{13}$ & (6.4~$\pm$~1.3)~$\times$~10$^{-4}$ \\ 40 K & $<$2.4~$\times$~10$^{11}$ & 1.8~$\times$~10$^{13}$ & $<$1.9~$\times$~10$^{-4}$ & (7.5~$\pm$~1.2)~$\times$~10$^{11}$ & (1.8~$\pm$~0.2)~$\times$~10$^{13}$ & (6.0~$\pm$~1.1)~$\times$~10$^{-4}$ \\ 50 K &$<$2.8~$\times$~10$^{11}$ & 2.2~$\times$~10$^{13}$ & $<$1.8~$\times$~10$^{-4}$ & (8.9~$\pm$~1.4)~$\times$~10$^{11}$ & (2.2~$\pm$~0.2)~$\times$~10$^{13}$ & (5.9~$\pm$~1.0)~$\times$~10$^{-4}$ \\ 70 K & $<$3.7~$\times$~10$^{11}$ & 3.1~$\times$~10$^{13}$ & $<$1.7~$\times$~10$^{-4}$ & (1.2~$\pm$~0.2)~$\times$~10$^{12}$ & (3.0~$\pm$~0.3)~$\times$~10$^{13}$ & (5.7~$\pm$~1.1)~$\times$~10$^{-4}$ \\ \hline \end{tabular}} \smallskip $^1$ We assume HCO$^+$/H$^{13}$CO$^+$~=~70 \citep{Wilson99}. \end{table}