We present a deep , narrow J –band search for proto–galactic Ly { \alpha } emission at redshifts z \sim 9 .
We combine an exceptionally deep image of the Hubble Deep Field South , obtained using a narrow band filter centred on the wavelength 1.187 \mu m using the VLT/ISAAC facility , with existing deep , broad band images covering optical to near infrared wavelengths .
We search for z \sim 9 Ly { \alpha } –emitting galaxies displaying a significant narrow band excess relative to the J _ { s } –band that are undetected at optical wavelengths .
We detect no sources consistent with this criterion to the 90 % point source flux limit of the NB image , F _ { NB } = 3.28 \times 10 ^ { -18 } ergs s ^ { -1 } cm ^ { -2 } .
The survey selection function indicates that we have sampled a volume of approximately 340 h ^ { -3 } Mpc ^ { 3 } to a Ly { \alpha } emission luminosity of 10 ^ { 43 } h ^ { -2 } ergs s ^ { -1 } .
We conclude by considering the potential implications for the physics of the high–redshift universe .