\begin{table}%t1
\caption{\label{table1}Main gamma-ray lines expected from the GC region}
%\centerline
{\begin{tabular}{ c c c c }
\hline
\hline\noalign{\smallskip}
Line energy & Nuclear    & {\it FWHM}$^a$ & Flux$^a$ \\
(MeV)       & Transition & (keV)                & cm$^{-2}$ s$^{-1}$   \\
\hline\noalign{\smallskip}
0.718 & $^{10}$B$^*_{0.718}$ $\rightarrow$ g.s.$^b$  & 30 & $3.4\times10^{-6}$ \\
0.847 & $^{56}$Fe$^*_{0.847}$ $\rightarrow$ g.s. & 6 &  $1.4\times10^{-6}$ \\
      & $^{27}$Al$^*_{0.844}$ $\rightarrow$ g.s. &   &   \\
1.809 & $^{26}$Mg$^*_{1.809}$ $\rightarrow$ g.s. & $<$2.7$^c$ & $3.5\times10^{-7}$ \\
      & ($^{26}$Al decay)                        &   &   \\
4.44  & $^{12}$C$^*_{4.439}$ $\rightarrow$ g.s.  & 160 & $1.2\times10^{-5}$ \\
      & $^{11}$B$^*_{4.445}$ $\rightarrow$ g.s.  &   &   \\
$\sim$5.2 & $^{14}$N$^*_{5.106}$ $\rightarrow$ g.s. & 280 & $5.4\times10^{-6}$ \\
          & $^{15}$O$^*_{5.181}$ $\rightarrow$ g.s. &     &   \\
          & $^{15}$O$^*_{5.241}$ $\rightarrow$ g.s. &     &   \\
          & $^{15}$N$^*_{5.270}$ $\rightarrow$ g.s. &     &   \\
          & $^{15}$N$^*_{5.299}$ $\rightarrow$ g.s. &     &   \\
$\sim$6.2 & $^{16}$O$^*_{6.130}$ $\rightarrow$ g.s. & 180$^d$ & $1.0\times10^{-5}$ \\
          & $^{15}$O$^*_{6.176}$ $\rightarrow$ g.s. &   &   \\
          & $^{15}$N$^*_{6.324}$ $\rightarrow$ g.s. &   &   \\
\hline
\end{tabular}}
\medskip
$^a$ {For $E_{\rm esc}=100$ MeV nucleon$^{-1}$ and $\sigma=0.05E_{\rm esc}$
(see Eq.~(4)). The fluxes are for the region of angular radius $\theta=5^\circ$ (see
Fig.~\ref{gamspatial} for fluxes at 4.44 and $\sim$6.2~MeV calculated for lower values of
$\theta$).}
$^b$ {Ground state.}
$^c$ {Assuming thermal broadening with $T<10$~keV.}
$^d$ {A very narrow line component at 6.129~MeV could arise from excitation
of $^{16}$O nuclei contained in micrometer-sized grains (see text).}\vspace*{3mm}
\end{table}