Year: 2015
Type: article
Abstract: We present a study of the cosmological Lyα 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 Hubble Space Telescope (HST) legacy fields and the abundance matching technique to associate UV emission and dust properties with the haloes, computing the emission from the interstellar medium (ISM) of galaxies and the intergalactic medium (IGM), including the effects of reionization, self-consistently. The Lyα 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. However the power spectrum is dominated by ISM emission on small scales (k > 0.01 h Mpc−1) with shot noise being significant only above k = 1 h Mpc−1. At very large scales (k < 0.01 h Mpc−1) diffuse IGM emission becomes important. The comoving Lyα luminosity density from IGM and galaxies, |$\dot{\rho }_{\rm {Ly\alpha } }^{\rm IGM} = 8.73(6.51) {\times} 10^{40}\,{\rm erg}\,{\rm s}^{-1 }\,{\rm Mpc}^{-3}$| and |$\dot{\rho }_{\rm {Ly\alpha } }^{\rm ISM} = 6.62(3.21) {\times} 10^{40}\,{\rm erg}\,{\rm s}^{-1}\,{\rm Mpc}^{-3}$| at z = 4(7), is consistent with recent Sloan Digital Sky Survey determinations. We predict a power k3PLyα(k, z)/2π2 = 9.76 × 10−4(2.09 × 10−5)nW2m−4 sr−2 at z = 4(7) for k = 0.1 h Mpc−1.
Authors: P. Comaschi, A. Ferrara
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W789862312