\begin{table}%t.C.4
%\centering
\par
\caption{Like Table~\ref{naphthalene} for the fluorene cation (C$_{13}$H$_{10}^+$).
\label{fluorene+}}
\begin{tabular}{cccc}
\hline \hline \noalign{\smallskip} 
& \multicolumn{3}{c}{Integrated flux} \\
\noalign{\smallskip} \cline{2-4} \noalign{\smallskip}
 & & Red & IRAS\\
Peak & ISRF & Rectangle & 21282+5050\\
($\mu$m) & (W$~~$sr$^{-1}$) (\%) & (W$~~$sr$^{-1}$) (\%)& (W$~~$sr$^{-1}$) (\%)\\ 
\hline \noalign{\smallskip}
$\perp$ 15.15 & $5.0\times 10^{-29}$ (0.90) & $2.4\times 10^{-27}$ (1.06) & $2.0\times 10^{-24}$ (0.68) \\
$\parallel$ 16.14 & $7.3\times 10^{-30}$ (0.13) & $3.7\times 10^{-28}$ (0.16) & $1.8\times 10^{-25}$ (0.06) \\
$\parallel$ 16.35 & $1.1\times 10^{-28}$ (1.91) & $5.1\times 10^{-27}$ (2.23) & $3.9\times 10^{-24}$ (1.37) \\
$\parallel$ 18.92 & $1.4\times 10^{-29}$ (0.26) & $7.2\times 10^{-28}$ (0.32) & $4.3\times 10^{-25}$ (0.15) \\
$[20.11]$ & $8.1\times 10^{-30}$ (0.15) & $3.7\times 10^{-28}$ (0.16) & -- \\
$[20.38]$ & $7.8\times 10^{-30}$ (0.14) & $4\times 10^{-28}$ (0.17) & -- \\
$[22.64]$ & $9.6\times 10^{-30}$ (0.17) & $4.5\times 10^{-28}$ (0.20) & -- \\
$\perp$ 22.84 & $3.1\times 10^{-29}$ (0.56) & $1.6\times 10^{-27}$ (0.71) & $9.9\times 10^{-25}$ (0.35) \\
$\parallel$ 24.23 & $1.2\times 10^{-29}$ (0.22) & $6.1\times 10^{-28}$ (0.27) & $2.1\times 10^{-25}$ (0.07) \\
$\perp$ 25.54 & $1.6\times 10^{-29}$ (0.30) & $9.3\times 10^{-28}$ (0.41) & $4.3\times 10^{-25}$ (0.15) \\
$[40.59]$ & $1.8\times 10^{-29}$ (0.33) & $7.2\times 10^{-28}$ (0.32) & -- \\
$\perp$ 43.62 & $2.7\times 10^{-29}$ (0.49) & $1.5\times 10^{-27}$ (0.64) & $6.7\times 10^{-25}$ (0.24) \\
$\parallel$ 47.31 & $2.2\times 10^{-29}$ (0.40) & $1.2\times 10^{-27}$ (0.52) & $2.5\times 10^{-25}$ (0.09) \\
$[78.65]$ & $2.6\times 10^{-29}$ (0.48) & $5.4\times 10^{-28}$ (0.24) & -- \\
$\perp$ 122.23 & $3.1\times 10^{-29}$ (0.56) & $1.7\times 10^{-27}$ (0.74) & $1.3\times 10^{-25}$ (0.04) \\
\hline 
\end{tabular}
\end{table}