Wednesday

I will present results from a new large (~4K) sample of Lyman-alpha (Lya) selected sources in 14 different redshift slices from z~2-6 in the COSMOS field (SC4K) using the INT and the Subaru telescopes. We select Lya emitters with a range of narrow and medium band filters and apply the same selection criteria, producing a comparable sample of Lya emitters which we use to explore the evolution of the Lya luminosity function across cosmic time in an unbiased way. Up to z~3, we find a deviation from a typical Schechter function for the brightest Lya luminosities, driven by an X-ray AGN population (spectroscopically supported) which boosts the Lyman-alpha emission. Beyond z~4, the Lya LF is very well described by a Schechter function only. Interestingly, we find that the Lya LF actually increases slightly from z~3 to z~6, just prior to the epoch of re-ionisation. Our results suggest that the Lya escape fraction at z~6 is typically very high, thus making Lya emitters very representative of the full Lyman-break population. I will conclude with preliminary results regarding the clustering and sizes of our SC4K sample. We will make the entire sample fully publicly available to the community.