Determine the origin of U13151’s dust-free appearance

Determine whether U13151 lacks substantial dust because it is undergoing its first major episode of star formation or because intense star formation has expelled or redistributed previously produced dust.

Background

U13151 shows negligible dust attenuation despite having a star-formation rate and specific star-formation rate high enough for radiation pressure and feedback to affect its gas and dust. The observations are consistent both with a genuinely young system in which dust has not yet accumulated and with a system in which dust formed earlier but was removed from or redistributed away from the compact UV-emitting regions.

Distinguishing these scenarios would constrain the timescale of dust production and feedback in ultra-low-mass galaxies during the first several hundred million years of cosmic history.

References

However, the current data cannot distinguish this scenario, and we do not attempt to discuss this further. Alternatively, following Occam's razor, U13151 may simply be undergoing its first major episode of star formation, with insufficient time for dust to build up efficiently within the system, as discussed by \citet{langeroodi_rapid_2024}.

— PRISMS/U13151. A Glimpse into the Earliest Phases of Galaxy Formation through an Ultra-Faint System $\approx$ 500 Myr after the Big Bang  (2610.26560 - Rinaldi et al., 19 Oct 2026) in Section 3.2.4, “UV-β slope, Burstiness, and Ionizing Photon Production Efficiency”