**Table 2:** Catalogs used for cross-identification
Catalog	$N_{\rm obj}$	$N_{\rm det}/N_{\rm unique}$	Id.Rad.	$\Delta$ RA	$\Delta$ Dec	$\rm Off_{50\%}$
			[ $^{\prime\prime}$ ]	[ $^{\prime\prime}$ ]	[ $^{\prime\prime}$ ]	[ $^{\prime\prime}$ ]
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	-
Walker (1956)	67	52/52	1.0	-0.45	0.08	0.47
Rebull et al. (2002)	511	236/235	1.5	0.73	-0.03	0.73
Lamm et al. (2004)	1598	305/299	1.0	-0.13	0.45	0.47
Dahm & Simon (2005)	229	183/183	1.0	-0.16	0.18	0.36
Flaccomio et al. (2000)	84	80/80	8.1-42.8^c	-0.85	1.49	3.70

^a $\max[2\sigma_{rd},1\hbox{$^{\prime\prime}$ }]$ . Mean/median: 1.74 $^{\prime\prime}$ /1.25 $^{\prime\prime}$ .
^b $\max[2(\sigma_{\rm RA}^2+\sigma_{\rm Dec}^2)^{1/2},0.5\hbox{$^{\prime\prime}$ }]$ . Mean/median: 0.54 $^{\prime\prime}$ /0.50 $^{\prime\prime}$ .
^c 85% point source encircled energy radii (Flaccomio et al. 2000). Mean/median: 12.0 $^{\prime\prime}$ /9.2 $^{\prime\prime}$ .

Source LaTeX | All tables | In the text