David Sobral
IA/U.Lisboa

Abstract
I will present new results regarding the first 2 Gyrs of cosmic time using very wide-field Lyman-alpha narrow-band surveys, including a large, matched Lya-Ha survey at z=2.23 to calibrate Lyman-alpha (CALYMHA). We are currently conducting and exploring unique ~10 deg^{^2} NB surveys with CFHT, Subaru and the INT to look for Lyman-alpha emitters at z=2.23-8.8. Surprisingly, we find a much higher space density of luminous Lyman-alpha emitters at z~6-7 than previously assumed, which we confirm spectroscopically with Keck and the VLT and that may be powered by PopIII stars. Our unique samples include sources even more luminous in Lyman-alpha than Himiko at z=6.6 (e.g. our CR7 galaxy), showing that ultra-luminous Lyman-alpha emitters are much more common than thought at z~6.6, with consequences for our understanding of re-ionisation and highly relevant for what J-PAS and EUCLID may be able to recover by conducting ultra-wide surveys.

4 February 2015, 13:30

Centro de Astrofísica
Rua das Estrelas
4150-762 Porto