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Abstract:

Over the last year, thanks to the JWST we have gathered detailed information on the rest-frame UV spectra of galaxies out to extremely high redshifts. Recent studies have ventured to investigate the evolution of the dust attenuation curves (using a Calzetti-like approach) out to z/sim 12. Complementing the UV data with sub-mm observation probing the rest frame FIR -- and thus cold ISM phases and dust -- has proven to be more challenging. Indeed, several ALMA follow-ups of JWST bright sources at z>8 have failed to detect the FIR continuum and bright lines such as [CII]158micron and [OIII]88micron. Zoom-in hydrodynamical simulations and theoretical models are thus fundamental to gaining a complete understanding of Epoch of Reionization galaxies' properties. We study the dust content, morphology, and resulting UV attenuation relying on RT post-processed zoom-in simulated galaxies from the SERRA and TNG suite, probing the wide redshift range z=0-7. We show that the IR emission morphology can be abundantly different than the UV one, which can explain the puzzling discrepancy between the very blue UV emission and large dust budgets inferred for z\sim 4-7 massive galaxies from the large programs REBELS and ALPINE. Even in local galaxies, we find that dust geometry plays a dominant role over global galaxy properties in shaping the slope and shape of the attenuation curve. This evidence questions the reliability of SED fitting-derived properties, relying on fixed local attenuation/extinction curve templates.