(Proposal ID) S11A-025

(PI) Sobral, David

(Proposal Title)
Subar-HiZELS: a matched Halpha & [OII] emission-line survey at z=1.5

(Abstract)
HiZELS, the Hi-Redshift(z) Emission Line Survey, is obtaining and exploring 
samples of 1000s of sources with strong emission lines (mostly Halpha) 
redshifted into the J, H and K bands using existing and custom-made narrow-
band filters. In the H band, the survey is finding hundreds of potential 
Halpha emitters at z = 1.47 which can be easily detected as [Oii]3727 emitters 
using the S-Camfs NB921 filter. Here, we propose to undertake a large 
(~5 deg^2) matched survey of Halpha and [Oii] at the same redshift, by far 
the most effective method of robustly selecting z = 1.47 line emitters. It 
will result in the largest and cleanest sample of Halpha+[Oii] emitters 
(~1000) at the peak of the star formation era of the Universe, probing a wide 
range of environments and overcoming cosmic-variance. The rich data-set will 
allow us to: 1) derive accurate luminosity functions for each line and provide 
the best measurement of the star formation rate density at that epoch; 2) 
probe inter-dependences between mass, environment, Halpha/[Oii] ratios and 
Halpha or [Oii] luminosity at z ~ 1.5, comparing those with the results from 
z ~ 0 and z = 2.23 (from HiZELS), 3) investigate and calibrate [Oii] as a star-
formation indicator for z > 1.5 and 4) present the first highly reliable 
clustering measurement of [Oii] and Halpha emitters at z = 1.47.