The file 

xbootes_cat_xray_opt_IR_21jun_v1.0.txt 

is version 1.0 (June 21, 2005) of the catalog of the X-ray sources
from the XBootes survey matched to their candidate optical and near-IR
counterparts from the NOAO Deep Wide-Field Survey (NDWFS).  The
XBootes Survey is a 5-ks Chandra imaging survey (PIs Murray and Jones;
Murray et al.2005) covering the Bootes Field of the NDWFS.  The NDWFS
is a deep optical (Bw,R,I) and near-IR (K) band imaging survey of the
same field (Jannuzi and Dey 1999, ASP, 191, 111).

This catalog (file) presents the 3,213 X-ray point-sources in the
XBootes survey whose positions fall within the NDWFS survey area. The
X-ray source properties are reproduced from Kenter et al. 2005, ApJS,
161, 9.  The matching of these sources to optical and near-IR
counterparts is described by Brand et al. 2006, ApJ, in press. The
optical and near-IR source properties are taken from the third data
release (DR3) of the NDWFS (Jannuzi et al. in prep; Dey et al. in
prep).


The sources were matched using a Bayesian identification scheme (see
Brand et al. 2006 for details). All optical sources with >1%
probability of being the match to an X-ray source are included. To
select only the most probable optical counterpart (including no
optical counterpart), one should select only the sources with optical
rank=1.