The next decade will see many new surveys pushing observations of galaxies to ever higher redshifts in order to get a better understanding of galaxy formation, and to constrain reionisation. One of the most promising methods for the detection of z > 7 galaxies is that of narrow-band imaging for Lyman-alpha emitters. In this talk I will present one such future, large potential survey; a Public Survey with VISTA (Visible and Infrared Survey Telescope for Astronomy) called ELVIS – Emission Line galaxies with VISTA Survey, a sub-survey of the Ultra-VISTA survey. ELVIS will survey four strips on the sky, covering 0.9 square degree in total, in the COSMOS field with a narrow-band filter centred on 1185 nm (J-band). This wavelength corresponds to Ly-alpha at z = 8.8, [OII] at z = 2.2, H-beta and [OIII] at z = 1.4 and H-alpha at z = 0.8. The science case for this survey is of interest to many as it enables the study of emission-line galaxy properties over a large redshift span. The Ly-alpha emitters can be used to study reionisation in the early Universe and galaxy formation, the intermediate redshift emitters give clues on star formation history and the H-alpha emitters will map the faintest end of the luminosity function of this type of object at z = 0.8. In my talk I will present the survey plan and the science cases in detail. I will also present predictions on the number of emission-line galaxies expected in this public survey, and results from semi-analytical modeling of Ly-alpha emitters at z = 8.8.
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