Search for z~6.96 Ly-alpha emitters with Magellan/IMACS in the COSMOS
  field
  We report a search for z~6.96 Ly-alpha emitters (LAEs) using a Narrow-Band
filter, centered at 9680 Angstroms, with the IMACS instrument on the Magellan
telescope at Las Campanas Observatory. We obtain a sample of 6 Ly-alpha emitter
candidates of luminosity ~10^42 erg/s in a total area of 465 square arcmin
corresponding to a comoving volume of ~ 72000 Mpc^3. From this result, we
derive a Ly-alpha luminosity function (LF) at z~6.96 and compare our sample
with the only z~6.96 Ly-alpha emitter spectroscopically confirmed to date (Iye
et al. 2006). We find no evolution between the z=5.7 and z~7 Ly-alpha
luminosity functions, if a majority of our candidates are confirmed.
Spectroscopic confirmation for this sample will enable more robust conclusions.
