Characterize the spectral properties and emission mechanisms of the hot exozodiacal dust

Characterize the spectral properties of the β Pictoris hot exozodiacal dust by determining the relative contributions of thermal emission and scattered light and by testing whether those contributions vary temporally.

Background

The L-band spectral slope is interpreted using a simplified single-grain, single-temperature model, which suggests submicron-sized grains. The authors explicitly note that the dust likely spans a range of grain sizes and temperatures and that scattering may dominate in the H band while thermal emission dominates in the L band. The relative contribution of these mechanisms, and possible temporal variability, therefore remains unresolved and requires a more detailed investigation.

References

However, this analysis assumes emission from a single grain at a single temperature, whereas the hot dust likely spans a range of sizes and temperatures. Moreover, the relative contribution of scattered light versus thermal emission remains uncertain. As discussed in \citet{Defrere_2012_betapic}, scattering may dominate in the H band, while thermal emission prevails in the L band. A detailed investigation of the spectral properties of this hot exozodi, possibly affected by temporal variability, is beyond the scope of this paper and is deferred to future work.

— VLTI/MATISSE observations of the hot dust around $β$ Pictoris: Observing faint objects with MATISSE  (2609.29783 - Priolet et al., 24 Sep 2026) in Section 4.2, On the spectral slope