ZEN 2 : A narrow J - band search for z ∼ 9 Ly α emitting galaxies directed towards three lensing clusters

We present the results of a continuing survey to detect Lyα emitting galaxies at redshifts z ∼ 9 : the ZEN (“z equals nine”) survey. We have obtained deep VLT/ISAAC observations in the narrow J–band filter NB119 directed towards three massive lensing clusters: Abell clusters 1689, 1835, and 114. The foreground clusters provide a magnified view of the distant universe and permit a sensitive test for the presence of very high-redshift galaxies. We search for z ∼ 9 Lyα emitting galaxies displaying a significant narrow-band excess relative to accompanying J-band observations that remain undetected in HST/ACS optical images of each field. No sources consistent with this criterion are detected above the unlensed 90% point-source flux limit of the narrow-band image, FNB = 3.7 × 10 −18 erg s cm . To date, the total coverage of the ZEN survey has sampled a volume at z ∼ 9 of approximately 1700 co-moving Mpc to a Lyα emission luminosity of 10 erg s. We conclude by considering the prospects for detecting z ∼ 9 Lyα emitting galaxies in light of both observed galaxy properties at z < 7 and simulated populations at z > 7.