Narrow-band search for Redshift 7.7 Lyman-(alpha) Galaxies
Abstract
Ly(alpha) galaxies offer a robust probe of the central phase of cosmological reionization: Because the Ly(alpha) emission line will be attenuated by neutral gas, the redshift evolution of observed Ly(alpha) galaxy numbers is strongly sensitive to the transition from an ionized to a neutral intergalactic medium. We propose 5 nights with NEWFIRM for a sensitive Lyα galaxy search, using a new, optimally designed filter of width 35Å, placed in a dark gap in the OH airglow spectrum. With this configuration (instead of earlier 9 Afilters at (lambda)=1.063; (mu) m; Tilvi et al 2010), we will double the survey volume and improve the sensitivity allowing us to reach 0.8×L_star. With the proposed survey we should expect ngal z=7.7 Lyα emitters for a non-evolving luminosity function. This will allow us to place statistical constraints on the attenuation of Lyα, which is a signature of a neutral IGM. These observations will offer a powerful prbe to constrain reionization at z=7.7. This survey will also provide a large sample of intermediate redshift emission line galaxies (H(alpha), [OIII], and [OII] at z=0.6, 1.1, and 1.8), thus probing the peak of the star formation activity. This program was given 6 nights in 2010A, but weather and instrumentation problems yielded equivalent of 2 nights worth of data. To find high redshift galaxies we need the full depth of the survey.
- Publication:
-
NOAO Proposal
- Pub Date:
- February 2012
- Bibcode:
- 2012noao.prop..581R