Constraining the Minimum Halo Mass that Supports Water Formation in a CCSN Remnant

Abstract

We present a simulation probing the formation of water in the remnant of low-mass Population III supernovae in a cosmological minihalo, and provide a tentative lower mass limit on host minihaloes that can recollapse on a short enough timescale and efficiently mix metals at high densities. We start from cosmological initial conditions and end the simulation when the central density undergoes catastrophic recollapse, whereby the water abundance is reported. During the Population III stars lifetime, the minihalo (M$ = 5 \times 10^5$ M$_{\odot}$) becomes blown out, and consequently the faint supernova explosion (E$_{\mathrm{SN}} = 5\times 10^{50}$ ergs) is completely unconfined to the virial radius of the minihalo. At the end of the simulation there is no significant water formation anywhere throughout the remnant, and the central recollapsing region is inefficient at incorporating the first metals into itself, remaining at low metallicity. The majority of metals are ejected from the core via bipolar outflow into the void and reach a peak metallicity of $\mathrm{Z} \sim 10^{-6}\ \mathrm{Z}_{\odot}$ at very low densities. The mass of the minihalo is low enough such that the recollapse timescale is unreasonable for this configuration to be the primary avenue of water formation in the early universe. We also provide a comparison with a regular CCSN (E$_{\mathrm{SN}} = 10^{51}$ ergs) and find the same effect, but amplified. As such, we can suggest that the minimum minihalo mass required for a confined explosion, and therefore the possibility of water formation is at least $10^{6}$ M$_{\odot}$ and the chemo-thermal evolution of a supernova remnant is more sensitive to the mass of the host minihalo than the mass of the Population III star residing within it.