Slicing through COSMOS: the evolution of the Lyα luminosity function at z ~ 2 - 6 using narrow and medium bands
Exploring the High-Redshift Universe with Current and Future Facilities
Date Submitted
2017-04-14 14:39:50
Sergio Santos
Lancaster University
David Sobral (Lancaster), Jorryt Matthee (Leiden), Joao Calhau (Lancaster)
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.
Schedule
id
date time
09:00 - 10:30
09:30
Abstract
Slicing through COSMOS: the evolution of the Lyα luminosity function at z ~ 2 - 6 using narrow and medium bands