We study the formation and destruction of molecules in the ejecta of Population III supernovae ( SNe ) using a chemical kinetic approach to follow the evolution of molecular abundances from day 100 to day 1000 after explosion .
The chemical species included in the study range from simple di-atomic molecules to more complex dust precursor species .
All relevant molecule formation and destruction processes that are unique to the SN environment are considered .
Our work focuses on zero-metallicity progenitors with masses of 20 , 170 , and 270 M _ { \odot } , and we study the effect of different levels of heavy element mixing and the inward diffusion of hydrogen and helium on the ejecta chemistry .
We show that the ejecta chemistry does not reach a steady state within the relevant timespan ( \sim 3 yr ) for molecule formation , thus invalidating previous results relying on this assumption .
The primary species formed in the harsh SN environment are O _ { 2 } , CO , SiS , and SO .
The SiO , formed as early as 200 days after explosion , is rapidly depleted by the formation of silica molecular precursors in the ejecta .
The rapid conversion of CO to C _ { 2 } and its thermal fractionation at temperatures above 5000 K allow for the formation of carbon chains in the oxygen-rich zone of the unmixed models , providing an important pathway for the formation of carbon dust in hot environments where the C/O ratio is less than 1 .
We show that the fully-mixed ejecta of a 170 M _ { \odot } progenitor synthesizes 11.3 M _ { \odot } of molecules whereas 20 M _ { \odot } and 270 M _ { \odot } progenitors produce 0.78 , and 3.2 M _ { \odot } of molecules , respectively .
The admixing of 10 % of hydrogen into the fully-mixed ejecta of the 170 M _ { \odot } progenitor increases its molecular yield to \sim 47 M _ { \odot } .
The unmixed ejecta of a 170 M _ { \odot } progenitor supernova without hydrogen penetration synthesizes \sim 37 M _ { \odot } of molecules , whereas its 20 M _ { \odot } counterpart produces \sim 1.2 M _ { \odot } .
This smaller efficiency at forming molecules is due to the large fraction of He ^ { + } in the outer mass zone of the ejecta .
Finally , we discuss the cosmological implication of molecule formation by Pop .
III SNe in the early universe .