Abstract Recent JWST observations reveal massive, UV-bright galaxies at z > 10 with little apparent dust attenuation, whereas Atacama Large Millimeter/submillimeter Array detections at z ≃ 7 show similarly massive systems that are already dust-rich and IR-luminous. This raises a fundamental question: can a single physical model for star formation and dust production explain both populations across cosmic time? We address this using a minimal, physically motivated framework with only two free parameters—the instantaneous star formation efficiency ( ϵ ⋆ ) and the dust yield per Type II supernova ( y d )—and predict the rest-frame UV and IR luminosity functions (LFs) from z ≃ 14 to 7. For a uniform interstellar medium (ISM), we find a UV–IR tension at the bright end of the LFs at z ≥ 7. The UV LF requires low dust yields ( y d ≲ 0.01 M ⊙ ), while the z = 7 IRLF requires high yields ( y d ∼ 0.1 M ⊙ ) unless the star formation efficiency is boosted above ϵ ⋆ ≈ 5%–10%. We show that incorporating a porous, turbulent ISM largely resolves this tension: turbulence opens low-column-density sight lines that enhance the UV escape fraction while leaving the total absorbed energy—and thus the IR luminosity—nearly unchanged once radiative-transfer-induced flattening of the attenuation curve is included. Large-grain dust distributions, while reducing UV opacity, become secondary once ISM porosity and radiative transfer are taken into account. At z > 10, however, even strong turbulence cannot reproduce the bright end of the UVLF at high dust yield. This could be resolved by efficient dust removal in early massive systems or substantial ISM dust growth by z ≃ 7. Our results highlight dust physics as a key lever for interpreting the rapidly growing UV and IR observational constraints within the broader context of early galaxy formation.
Sommovigo et al. (Fri,) studied this question.
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