2018MNRAS.477.5406Y

Understanding Lyαemitting galaxies (LAEs) can be a key to reveal cosmic reionization and galaxy formation in the early Universe. Based on halo merger trees and Lyαradiation transfer calculations, we model redshift evolution of LAEs and their observational properties at z >= 6. We consider ionized bubbles associated with individual LAEs and IGM (integer-galactic medium) transmission of Lyαphotons. We find that Lyαluminosity tightly correlates with halo mass and stellar mass, while the relation with star formation rate has a large dispersion. Comparing our models with the observed luminosity function by Konno et al., we suggest that LAEs at z ∼ 7 have galactic wind of V_ out_ ≳100 km s^–1 and H I column density of N_ HI_ ≳10²⁰ cm^–2. Number density of bright LAEs rapidly decreases as redshift increases, due to both lower star formation rate and smaller H II bubbles. Our model predicts future wide deep surveys with next-generation telescopes, such as James Webb Space Telescope, European Extremely Large Telescope, and Thirty Metre Telescope, can detect LAEs at z ∼ 10 with a number density of n_ LAE_ ∼a few ×10^–6 Mpc^–3 for the flux sensitivity of 10^–18 erg cm^–2 s^–1. When giant H II bubbles are formed by clustering LAEs, the number density of observable LAEs can increase by a factor of few. By combining these surveys with future 21-cm observations, it could be possible to detect both LAEs with L_ Lyα_≳10⁴² erg s^–1 and their associated giant H II bubbles with the size ≳250 kpc at z ∼ 10.