Broadband Imaging Segregation of z ~ 3 Ly-alpha Emitting and Ly-alpha Absorbing Galaxies

Understand

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.