The distribution of Lyα-emitting galaxies at z=2.38

We present the detection of 34 Lyalpha emission-line galaxy candidates in a 80 x 80 x 60 comoving Mpc region surrounding the known z = 2.38 galaxy cluster J2143-4423. The space density of Lyalpha emitters is comparable to that found by Steidel et al. when targeting a cluster at redshift 3.09, which is a factor of 5.8 +/- 2.5 greater than that found by field samples at similar redshifts. The distribution of these galaxy candidates contains several 5-10 Mpc scale voids. We compare our observations with mock catalogs derived from the VIRGO consortium LambdaCDM n-body simulations. Fewer than 1% of the mock catalogs contain voids as large as we observe. Our observations thus tentatively suggest that the galaxy distribution at redshift 2.38 contains larger voids than predicted by current models. Three of the candidate galaxies and one previously discovered galaxy have the large luminosities and extended morphologies of "Lyalpha blobs.''