Spherically symmetric NLTE model atmospheres of hot hydrogen-helium first stars

TL;DR

This paper models the atmospheres of hot Population III stars with hydrogen and helium, calculating their emergent fluxes and ionizing photon outputs over time to understand their impact on early universe ionization.

Contribution

It introduces a new NLTE modeling approach for Population III stars' atmospheres, including time-dependent ionizing photon flux calculations.

Findings

Calculated ionizing photon fluxes for early stars.

Demonstrated the evolution of photon fluxes over time.

Provided flux data for understanding early universe reionization.

Abstract

We present results of our calculations of NLTE model stellar atmospheres for hot Population III stars composed of hydrogen and helium. We use our own computer code for calculation of spherically symmetric NLTE model atmospheres in hydrostatic and radiative equilibrium. The model atmospheres are then used for calculation of emergent fluxes. These fluxes serve for the evaluation of the flow of high-energy photons for energies higher than ionization energies of hydrogen and helium, the so-called ionizing photon fluxes. We also present the time evolution of the ionizing photon fluxes.