Broadband Imaging Segregation of z ~ 3 Ly-alpha Emitting and Ly-alpha
  Absorbing Galaxies
  The spectral properties of Lyman break galaxies (LBGs) offer a means to
isolate pure samples displaying either dominant Ly-alpha in absorption or
Ly-alpha in emission using broadband information alone. We present criteria
developed using a large z ~ 3 LBG spectroscopic sample from the literature that
enables large numbers of each spectral type to be gathered in photometric data,
providing good statistics for multiple applications. In addition, we find that
the truncated faint, blue-end tail of z ~ 3 LBG population overlaps and leads
directly into an expected Ly-alpha emitter (LAE) population. As a result, we
present simple criteria to cleanly select large numbers of z ~ 3 LAEs in deep
broadband surveys. We present the spectroscopic results of 32 r' <~ 25.5 LBGs
and r' <~ 27.0 LAEs at z ~ 3 pre-selected in the Canada-France-Hawaii Telescope
Legacy Survey that confirm these criteria.
