\begin{table}%t1
\caption{\label{t1}Peak position and assignments for irradiated CO; $A$ is the corresponding band strength.}
 %\centering
\par
  \begin{tabular}{l l l l l}
  \hline \hline\noalign{\smallskip}
  Position (cm$^{-1}$) & Molecule                        & Assignment             & $A$ ($10^{-17}$ cm/molecule) & Reference                 \\
  \hline
  4694                 & ?                               &                        &                            &                           \\
  4252                 & CO                              & 2$\nu_{1}$             &                            & Jamieson et~al. (\cite{Jamieson2006})    \\
  3707                 & CO$_{2}$                        & $\nu_{1} + \nu_{3}$    &                            & Gerakines et~al. (\cite{Gerakines1995})   \\
  3602                 & CO$_{2}$                        & 2$\nu_{2} + \nu_{3}$   &                            & Gerakines et~al. (\cite{Gerakines1995})   \\
  3070                 & C$_{3}$O$_{2}$                  & $\nu_{2} + \nu_{3}$    &                            & Gerakines \& Moore (\cite{Gerakines2001}) \\
  2399                 & C$_{3}$O$_{2}$                  & $\nu_{2} + \nu_{4}$    &                            & Gerakines \& Moore (\cite{Gerakines2001}) \\
  2346                 & CO$_{2}$                        & $\nu_{3}$              & 7.6                        & Yamada \& Person (\cite{Yamada1964})   \\
  2330                 & OC$^{18}$O                      & $\nu_{3}$              &                            & Jamieson et~al. (\cite{Jamieson2006})    \\
  2281                 & $^{13}$CO$_{2}$                 & $\nu_{3}$              &                            & Gerakines et~al. (\cite{Gerakines1995})   \\
  2257                 & C$_{5}$O                        &                        &                            & Dibben et~al. (\cite{Dibben2000})      \\
  2247                 & C$_{3}$O                        & $\nu_{1}$              &                            & Jamieson et~al. (\cite{Jamieson2006})    \\
  2242                 & C$_{3}$O$_{2}$                  & $\nu_{3}$              & 13                         & Gerakines \& Moore (\cite{Gerakines2001}) \\
  2209                 & CO                              & $\nu_{1} + \nu_{L}$    &                            & Jamieson et~al. (\cite{Jamieson2006})    \\
  2193                 & C$_{3}$O$_{2}$                  & $\nu_{1}$              &                            & Jamieson et~al. (\cite{Jamieson2006})    \\
  2139                 & CO                              & $\nu_{1}$              & 1.1                        & Jiang et~al. (\cite{Jiang1975})       \\
  2123                 & C$_{4}$O$_{2}$ or C$_{7}$O$_{2}$& $\nu_{2}$              &                            & Jamieson et~al. (\cite{Jamieson2006})    \\
  2112                 & C$^{17}$O                       & $\nu_{1}$              &                            & Palumbo et~al. (\cite{Palumbo2008})    \\
  2107                 & C$_{5}$O and O$_{3}$            & $\nu_{2}$; $\nu_{1}$ + $\nu_{3}$    &               & Jamieson et~al. (\cite{Jamieson2006}); Bennet \& Kaiser (\cite{Bennet2005}) \\
  2092                 & $^{13}$CO                       & $\nu_{1}$              &                            & Gerakines et~al. (\cite{Gerakines1995})   \\
  2088                 & C$^{18}$O                       & $\nu_{1}$              &                            & Jamieson et~al. (\cite{Jamieson2006})    \\
  2074                 & ?                               &                        &                            & Freivogel et~al. (1996)   \\
  2071                 & ?                               &                        &                            &                           \\
  2070                 & ?                               &                        &                            &                           \\
  2065                 & ?                               &                        &                            & Szczepanski et~al. (\cite{Szczepanski1996}) \\
  2060                 & C$_{5}$O$_{2}$                  & $\nu_{3}$              & 7.4                        & Jamieson et~al. (\cite{Jamieson2006})    \\
  2039                 & C$_{3}$                         & $\nu_{3}$              & 13                         & Jamieson et~al. (\cite{Jamieson2006})    \\
  2019                 & ?                               &                        &                            &                           \\
  1989                 & C$_{2}$O                        & $\nu_{1}$              & 2.4                        & Jamieson et~al. (\cite{Jamieson2006})    \\
  1950                 & C$_{6}$                         &                        &                            & Trottier \& Brooks        \\
  1915                 & C$_{4}$O                        & $\nu_{2}$              &                            & Jamieson et~al. (\cite{Jamieson2006})    \\
  1874                 & ?                               &                        &                            &                           \\
  1859                 & ?                               &                        &                            &                           \\
  1817                 & C$_{5}$O                        & $\nu_{3}$              & 6.2                        & Jamieson et~al. (\cite{Jamieson2006})    \\
  1303                 & ?                               &                        &                            &                           \\
  1041                 & O$_{3}$                         &                        & 1.53                       & Bennet \& Kaiser (\cite{Bennet2005})   \\
  879                  & ?                               &                        &                            &                           \\
  659                  & CO$_{2}$                        & $\nu_{2}$              &                            &                           \\
  \hline
  \end{tabular}
\end{table}