Constraining dust formation in high-redshift young galaxies

Abstract

Core-collapse supernovae (SNe) are believed to be the first significant source of dust in the Universe. Such SNe are expected to be the main dust producers in young high-redshift Lyman α emitters (LAEs) given their young ages, providing an excellent testbed of SN dust formation models during the early stages of galaxy evolution. We focus on the dust enrichment of a specific, luminous LAE (Himiko, z ≃ 6.6) for which a stringent upper limit of 52.1 μJy (3σ) has recently been obtained from Atacama Large Millimetre/submillimetre Array continuum observations at 1.2 mm. We predict its submillimetre dust emission using detailed models that follow SN dust enrichment and destruction and the equilibrium dust temperature, and obtain a plausible upper limit to the dust mass produced by a single SN: md, SN < 0.15-0.45M⊙, depending on the adopted dust optical properties. These upper limits are smaller than the dust mass deduced for SN 1987A and that predicted by dust condensation theories, implying that dust produced in SNe are likely to be subject to reverse shock destruction before being injected into the interstellar medium. Finally, we provide a recipe for deriving md, SN from submillimetre observations of young, metal-poor objects wherein condensation in SN ejecta is the dominant dust formation channel. © 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.