A Supernova-driven Wind Model for High-z Galaxies

Abstract

A supernova‐driven wind model for high‐z galaxies such as Lyman alpha emitters (LAEs) and Lyman break galaxies (LBGs) is constructed using high‐resolution three‐dimensional hydrodynamic simulations. Our simulations use a hybrid N‐body/hydrodynamics code which is applicable to a complex system consisting of dark matter, stars and gas. The gas is allowed to form stars and is subject to physical processes such as the radiative cooling and the energy feedback from SNe. We have performed a parameter study varying the total halo mass. The results indicate that the high‐density cooling gas radiate intensive Lyman alpha emission with luminosity of 1041–44 ergs s−1, depending on the total halo mass. In addition, we show the evolutionary tracks of chemical properties. Moreover, in order to assess the contribution of LBGs and LAEs at redshifts 3<z<7 to the ionization of intergalactic medium, we investigate the escape fractions of ionizing photons from these galaxies by solving the three‐dimensional radiative transfer. The resultant escape fractions are 0.07–0.47 for LAEs and 0.06–0.17 for LBG. These results are well concordant with the recent estimations derived from the flux ratio at 1500 angstrom to 900 angstrom of LAEs and LBGs.