\begin{table}%t2
\caption{\label{tab-mod}Model parameters for the different solutions.}
%\centerline
 {\small \begin{tabular}{clcccccc}
\hline \hline  \noalign{\smallskip}
Solution  & Code &$F_{s+c}$ &  $\alpha$ &  $\Delta Q_{\rm H_2O}/Q_{\rm H_2O}$ & $\Delta Q_{\rm CO}/Q_{\rm CO}$ & $Q_{\rm H_2O}$
&  $Q_{\rm CO}$ \\
& & $^a$ & $^b$ & $^c$ &$^d$ & \multicolumn{2}{c}{molecules~s$^{-1}$}\\
\hline \noalign{\smallskip}
\#1 & HBH   & 0.05  & 0.45 & 0\% &  0\% & (0.88--1.72) $\times 10^{31}$ &$(3.27 \pm 0.03 )\times 10^{30}$ \\
\#2 & HBH06C & 0.05 & 0.45 & 0\% & 30\% & (0.87--1.73) $\times 10^{31}$ &$(1.30 \pm 0.08)\times 10^{30}$\\
\#3 & HBH06D & 0.5 & 0.45 & 0\% & 30\% & (1.38--1.62) $ \times 10^{31}$ & $(1.32 \pm 0.07) \times 10^{30}$  \\
\#4 & HBH06E & 0.5 & 0.45 & $\simeq$5\% & 30\% & (1.19--1.50) $\times 10^{31}$ & $(1.27 \pm 0.02) \times 10^{30}$  \\
\#5 & HBH06F & 0.5 & SMALL & $\simeq$5\% & 30\% & (1.39 --1.65) $\times 10^{31}$ & $(1.29 \pm 0.04) \times 10^{30}$  \\
 \hline
\end{tabular}}
\medskip
$^a$ $F_{s+c}$ is the fraction of the solar flux assumed scattered towards the shadowed surface elements of the nucleus by dust particles; $^b$~parameter controlling the day-night asymmetry of photodissociative heating; $^c$ excess water production (under peak solar illumination) due to an assumed increase of the icy fraction inside the enhanced CO~flux area; $^d$ fraction of $Q_{\rm CO}$ produced inside the enhanced CO~flux area. 
\vspace*{3mm}
 \end{table}