Metal Enrichment of the Primordial Interstellar Medium through Three-dimensional Hydrodynamical Evolution of the First Supernova Remnant

Abstract

The long-term evolution of supernova (SN) remnants in the primordial interstellar medium (ISM) with an inhomogeneous structure is calculated to investigate metal enrichment of the primordial gas. For this purpose, we have constructed a parallel three-dimensional hydrodynamics code incorporating the radiative cooling and self-gravity. The self-gravity and radiative cooling develop the inhomogeneous structure of the ISM from a small perturbation with a power-law spectrum. The resultant density ranges from 0.5 to 10 6 cm -3 . Calculations for an SN with the progenitor mass of 20 M ⊙ are performed as the first step of a series of our study. It is found from the results that a single SN distributes some of the newly synthesized heavy elements into a dense filament of the ISM with densities ranging from 100 to 10 4 cm -3 depending on where the SN explodes. Thus, the metallicity [Mg/H] of the dense filaments polluted by the SN ejecta becomes -2.7 ± 0.5. From these filaments, the first Population II stars will form. This value is in accordance with previous analytical work by Shigeyama & Tsujimoto with an accuracy of ∼0.3 dex.