Dust in the first galaxies

Abstract

Using cosmological volume simulations and a custom built sub-grid model for Pop~III star formation, we examine the baseline dust extinction in the first galaxies due to Pop~III metal enrichment in the first billion years of cosmic history. We find that while the most enriched, high-density lines of sight in primordial galaxies can experience a measurable amount of extinction from Pop~III dust ($E(B-V{)}_{\max }=0.07,A_{\mathrm{V},\max }\approx 0.28$), the average extinction is very low with $⟨E(B-V)⟩\lesssim 10^{-3}$. We derive a power-law relationship between dark matter halo mass and extinction of $E(B-V)\propto M_{\mathrm{halo}}^{0.80}$. Performing a Monte Carlo parameter study, we establish the baseline reddening of the UV spectra of dwarf galaxies at high redshift due to Pop~III enrichment only. With this method, we find $⟨{\beta }_{\mathrm{UV}}⟩-2.51\pm 0.07$, which is both nearly halo mass and redshift independent.

Published 01/2018 pages, 5 figures

References in corpus (4)

• The First Billion Years Project: The escape fraction of ionizing photons in the epoch of reionization
• Simulating cosmic metal enrichment by the first galaxies
• The spectral evolution of the first Galaxies. III. Simulated James Webb Space Telescope spectra of reionization-epoch galaxies with Lyman continuum leakage
• On the (in)variance of the dust-to-metals ratio in galaxies

Cited by in corpus (1)

• Conditions for Reionizing the Universe with A Low Galaxy Ionizing Photon Escape Fraction