Thesan-Zoom Simulations Show Bursty Star Formation Destroys Dust Reservoirs Faster Than Standard Models Predict
Thesan-Zoom radiation-hydrodynamical simulations link bursty star formation to rapid dust destruction at z ≥ 3, producing short-lived IR-bright phases and insufficient attenuation. This tension implies burstiness must subside by z ∼ 8 to match observed high-redshift dust reservoirs, or current models lack key dust-shielding mechanisms.
The Thesan-Zoom suite self-consistently tracks dust formation, growth, and destruction coupled to radiative transfer across a multiphase ISM. Galaxies reproduce observed dust-to-gas and dust-to-metal trends with metallicity yet exhibit a clear deficit at high specific star-formation rates. Post-processing for unresolved dust still underpredicts 1500 Å attenuation, indicating that current feedback implementations destroy grains too efficiently during starbursts. This time-variable behavior naturally generates the observed correlation between dust temperature and offset from the star-forming main sequence. Standard semi-analytic models assume smoother star-formation histories that allow dust to accumulate and survive; Thesan-Zoom demonstrates that realistic burstiness erases these reservoirs on timescales shorter than replenishment. The result directly challenges explanations for the UV-luminous galaxy population at z ≥ 10 that rely on sustained low-dust conditions without rapid subsequent dust build-up. JWST and ALMA dust-mass measurements at z ∼ 8 will test whether burstiness must decline sharply or whether additional shielding physics is missing from the simulations.
Thesan-Zoom team: ALMA or JWST dust-mass surveys will detect M_dust/M_star ≥ 10^{-3} reservoirs in fewer than 20% of galaxies at 8 < z < 10 unless star-formation burstiness declines below current simulated levels by z = 8.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2607.08824)
- [2]Supporting Source(https://arxiv.org/abs/2302.03042)