Determine the origin of KCFF#1’s extended mid-infrared emission

Determine whether the JWST/MIRI F560W, F770W, and F1000W filters primarily trace thermal continuum or scattered light, and whether polycyclic aromatic hydrocarbon features make a significant contribution to the extended emission associated with the KCFF#1 proplyd tail.

Background

KCFF#1 is the proplyd closest to the B1V star 42 Orionis and is exposed to an estimated far-ultraviolet field of approximately 105 G_0. JWST/MIRI imaging detects the disk and a dusty tail extending beyond 3000 au, providing spatially resolved information about material being removed from the disk.

The authors compare emission in the F560W, F770W, and F1000W filters and find no clear enhancement of polycyclic aromatic hydrocarbon features along the tail. However, they explicitly leave unresolved whether the observed broadband emission is dominated by thermal dust emission, scattered light, or contributions from polycyclic aromatic hydrocarbons. Resolving this issue would clarify the physical nature of the extended tail and the mechanisms of dust removal during advanced external photoevaporation.

References

Whether or not these MIRI filters are primarily tracing thermal continuum and/or scattered light and, if there is significant contributions from PAH features is unclear but, the F1000W filter is the brightest of the three which, covers the silicate feature, and when comparing MRS spectra extracted from the disk and the tail there is no clear enhancement in the PAH features along these streamlines leading us to believe that dust is responsible for this extended emission.

— JWST-MIRI's multi-dimensional view of mass loss in the irradiated disks of NGC 1977  (2608.17226 - Booth et al., 18 Aug 2026) in Section 3.2, “Extended continuum emission from KCFF#1”