2005ApJ...622L..77W

We have identified an obvious and strong large-scale structure at redshift z~5.75 in a wide (31'x33') field, narrowband survey of the Chandra Deep Field-South region. This structure is traced by 17 candidate Lyα emitters, among which 12 are found in an 823 nm filter (corresponding to Lyα at z=5.77±0.03) and five in an 815 nm image (z=5.70±0.03). The Lyα emitters in both redshift bins are concentrated in one quadrant of the field. The Hubble Ultra Deep Field, the Chandra Deep Field-South, and the Great Observatories Origins Deep Survey-South fields all lie near the edge of this overdensity region. Our results are consistent with reports of an overdensity in the Ultra Deep Field region at z~5.9. This structure is the highest redshift overdensity found so far.