\begin{table}%t5
\caption{\label{tab:xray}X-ray observations.} 
%%\centerline

{\begin{tabular}{ccccc}
\noalign{\smallskip}\hline\noalign{\smallskip}\hline\noalign{\smallskip}
ID& Count Rate& Flux$^a$                                & ${L_{\rm X}}^{a}$        & $S/N^{b}$\\
  & 0.3--4~keV& 0.5--2~keV                       &0.1--2.4~keV   &    \\
  & ($10^{-5}$)  & ($10^{-16}~{\rm erg}~{\rm s}^{-1}~{\rm cm}^{-2}$) &($10^{43}~{\rm erg}~{\rm s}^{-1}$) &     \\
\noalign{\smallskip}\hline\noalign{\smallskip}
1  & 8.49 &6.80--9.01&0.12--0.26& u.l.\\
2  & 5.56 &4.45-5.90&0.08--0.18& u.l.\\
3  & 10.1 &8.15--10.98&0.16--0.37& u.l.\\
4  & 11.2 &9.04--12.31&0.19--0.44& u.l.\\
5  & 23.7 &19.31--29.21&0.86--2.36& 11.3 \\
6  & 5.90 &3.04--4.14&0.26--0.76& u.l.\\
7  & 5.77 &2.97--4.05&0.26--0.74& u.l.\\
8  & 9.88 &5.10--6.91&0.47--1.37& u.l.\\
9  & 5.68 &3.08--4.14&0.83--3.67& u.l.\\
10 & 9.37 &5.39--7.54&3.50--22.43& u.l.\\
11 & 5.72 &3.29--4.69&2.27--15.06& u.l.\\
12 & 6.70 &3.85--5.50&2.66--17.64& u.l.\\
\noalign{\smallskip} \hline
\end{tabular}}
\medskip
\par
$^a$  Values for a Raymond-Smith model with assumed temperature
  respectevelly of 3~keV and 1~keV and metallicity 0.2 $Z_\odot$.\\
$^b$ u.l. indicates structures with a 3$\sigma$ upper limit in the~flux. 
\end{table}