Optical and Infrared Nondetection of thez= 10 Galaxy behind Abell 1835

Gravitational lensing by massive galaxy clusters is a powerful tool for thediscovery and study of high redshift galaxies, including those at z>=6 likelyresponsible for cosmic re-ionization. Pello et al. recently used this techniqueto discover a candidate gravitationally magnified galaxy at z=10 behind themassive cluster lens Abell 1835 (z=0.25). We present new Keck (LRIS) andSpitzer Space Telescope (IRAC) observations of the z=10 candidate (hereafter#1916) together with a re-analysis of archival optical and near-infraredimaging from the Hubble Space Telescope and VLT respectively. Our analysistherefore extends from the atmospheric cut-off at lambda_obs=0.35um out tolambda_obs=5um with Spitzer/IRAC. The z=10 galaxy is not detected in any ofthese data, including an independent reduction of Pello et al.'s discovery H-and K-band imaging. We conclude that there is no statistically reliableevidence for the existence of #1916. We also assess the implications of ourresults for ground-based near-infrared searches for gravitationally magnifiedgalaxies at z>~7. The broad conclusion is that such experiments remainfeasible, assuming that space-based optical and mid-infrared imaging areavailable to break the degeneracy with low redshift interlopers (e.g. z~2-3)when fitting spectral templates to the photometric data.Comment: Published in ApJ, 636, 575-58