Self-sustaining star formation fronts in filaments during cosmic dawn

TL;DR

This paper introduces a model where star formation in early cosmic filaments is triggered and sustained by shock fronts driven by supernova feedback, leading to rapid star formation in primordial, low-mass halos during reionization.

Contribution

The paper presents a novel self-sustaining shock front model for star formation in high-redshift filaments, linking shock dynamics with early star formation processes.

Findings

Star formation fronts propagate at 300-700 km/s during reionization.

Shock fronts cool and fragment gas into massive stars rapidly.

Future JWST observations could detect these star-forming regions.

Abstract

We propose a new model for the ignition of star formation in low-mass halos by a self-sustaining shock front in cosmic filaments at high redshifts. The gaseous fuel for star formation resides in low mass halos which can not cool on their own due to their primordial composition and low virial temperatures. We show that star formation can be triggered in these filaments by a passing shock wave. The shells swept-up by the shock cool and fragment into cold clumps that form massive stars via thermal instability on a timescale shorter than the front's dynamical timescale. The shock, in turn, is self-sustained by energy injection from supernova explosions. The star formation front is analogous to a detonation wave, which drives exothermic reactions powering the shock. We find that sustained star formation would typically propel the front to a speed of $\sim 300-700\,\rm km\,s^{-1}$ during the epoch of reionization. Future observations by the $\textit{James Webb Space Telescope}$ could reveal the illuminated regions of cosmic filaments, and constrain the initial mass function of stars in them.