Probing high-redshift galaxies with Ly$\alpha$ intensity mapping

Understand

We present a study of the cosmological Ly$\alpha$ emission signal at $z > 4$.

• Our goal is to predict the power spectrum of the spatial fluctuations that could be observed by an intensity mapping survey.
• The model uses the latest data from the HST legacy fields and the abundance matching technique to associate UV emission and dust properties with the halos, computing the emission from the interstellar medium (ISM) of galaxies and the intergalactic medium (IGM), including the effects of reionization, self-consistently.
• The Ly$\alpha$ intensity from the diffuse IGM emission is 1.3 (2.0) times more intense than the ISM emission at $z = 4(7)$; both components are fair tracers of the star-forming galaxy distribution.