\begin{table}%t5
 \caption{\label{table_PAHratios}Flux ratios of the PAH bands for the \textit{Spitzer IRS} spectrum at the center of the SQ~ridge, and the  \textit{ISO-CVF} spectrum of the diffuse Galactic light.}
 \small%\centering
\par
 \begin{tabular}{c c c c c}
	\hline
	\hline\noalign{\smallskip}
 & \multicolumn{4}{c}{Flux ratios} \\
\hline
& $R_{6.2/7.7}$ & $R_{7.7/11.3}$  & $R_{11.3/12.6}$ & $R_{11.3/17}$ \\ 
 SQ~ridge \textit{(IRS)} & $<$$0.2 $ & $1.36 \pm 0.07$ & $2.3 \pm 0.2$ & $3.01 \pm 0.16$ \\ 
Galactic \textit{(CVF)} & $0.272 \pm 0.005$ & $2.93 \pm 0.08$ & $2.24 \pm 0.07$ &  No data \\
\hline
\end{tabular}
 \vspace*{4mm}
\end{table}