z=2.4 Ly{alpha} emitters in the 53W002 field

A custom-made filter, NB413, centered at 4140{AA} with a width of 83{AA} is used to observe the 31'x24' area around the radio galaxy. We detected 204 Ly{alpha} emitters (LAEs) at z=2.4 with a rest-frame equivalent width larger than 25{AA} to the depth of 26 AB mag (in NB413).

The entire LAE population in the 53W002 field has an average number density and distributions of equivalent width and size that are similar to those of other fields at z~2. We identify a significant high-density region (53W002F-HDR) that spreads over {approx}5'x4' near 53W002, where the LAE number density is nearly four times as large as the average of the entire field. Using the probability distribution function of density fluctuation, we evaluate the rareness probability of 53W002F-HDR to be 0.9^+2.4^_-0.62_%, which corresponds to a moderately rich structure.