\begin{table}%t2
\caption{Catalogs used for cross-identification\label{tab:catalogs}}
%\centerline
{\begin{tabular}{l r r c c c c} 
\hline\hline
Catalog           & $N_{\rm obj}$&  $N_{\rm det}/N_{\rm unique}$   & Id.Rad.	& $\Delta$RA& $\Delta$Dec& $\rm Off_{50\%} $\\
                  &          &  	    & [\arcsec]   &   [\arcsec] & [\arcsec]   & [\arcsec]    \\
\hline
%  ACIS  	  &	 420 &  420/418	    & 1.0-12.6$^a$& -0.09	& -0.09        &  0.24 \\
  ACIS  	  &	 420 &  ---	    & 1.0$-$12.6$^a$& $-$0.09	& -0.09        &  0.24 \\
  2Mass 	  &	1098 &  346/344	    &  0.5$-$1.4$^b$&  0.00	&  0.00        &    -- \\
  \citet{walker56}&	  67 &    52/52	    &	  1.0	  & $-$0.45	&  0.08        &  0.47 \\
  \citet{reb02}   &	 511 &  236/235	    &	   1.5    &  0.73	& $-$0.03        &  0.73 \\
  \citet{lamm04}  &	1598 &  305/299	    &	   1.0    & $-$0.13	&  0.45        &  0.47 \\
  \citet{dahm05}  &	 229 &  183/183	    &	   1.0    & $-$0.16	&  0.18        &  0.36 \\
  \citet{fla00}   &	  84 &    80/80	    & 8.1$-$42.8$^c$& $-$0.85	&  1.49        &  3.70 \\
\hline 
\end{tabular}}\medskip
\par
$^a$ $\max[2\sigma_{rd},1\arcsec]$. Mean/median: 1.74\arcsec/1.25\arcsec.\\
$^b$ $\max[2(\sigma_{\rm RA}^2+\sigma_{\rm Dec}^2)^{1/2},0.5\arcsec]$.
Mean/median: 0.54\arcsec/0.50\arcsec. \\
$^c$ 85\% point source encircled energy radii \citep{fla00}.
Mean/median: 12.0\arcsec/9.2\arcsec.
\end{table}