\begin{table}%t1 \par \caption{\label{tab:ch}CH spectroscopic parameters for the $N = 1 \leftarrow 1$ transitions.} \begin{tabular}{lcccccl} \hline \hline \noalign{\smallskip} Frequency & Transition $u\!\gets\!\ell$ & $A_{u\ell}$ & $E_u/k$ & $\int\tau {\rm d}V/N$\tablefootmark{a} & $V_{\rm off}$ \\ MHz & $J',F' \!\gets \!J'',F''$ & 10$^{-4}$ s$^{-1}$ & K & $10^{-13}$ km~s$^{-1}$~cm$^2$ & \kms \\ \hline 532721.68 & $3/2,1^+ \!\gets\! 1/2,1^- $ & $2.07 $ & 25.7 & 0.055 & 1.3 \\ 532723.93 & $3/2,2^+ \!\gets\! 1/2,1^- $ & $6.21 $ & 25.7 & 0.275 & 0.0 \\ 532793.31 & $3/2,1^+ \!\gets\! 1/2,0^- $ & $4.14 $ & 25.7 & 0.110 & $-39.0$ \\ 536761.15 & $3/2,2^- \!\gets\! 1/2,1^+ $ & $6.38 $ & 25.8 & 0.276 & 0.0 \\ 536781.95 & $3/2,1^- \!\gets\! 1/2,1^+ $ & $2.13 $ & 25.8 & 0.055 & $-11.6$ \\ 536795.68 & $3/2,1^- \!\gets\! 1/2,0^+ $ & $4.25 $ & 25.8 & 0.111 & $-19.3$ \\ \hline \end{tabular} \tablefoot{\tablefoottext{a}{Opacity integrated over the line profile per total \CH\ column density, under the assumption that $T_{\rm ex} \ll E_u/k$.}} \end{table}