Formation mechanism of NGC 1514’s mid-infrared rings

Determine the physical mechanism responsible for the formation of the axisymmetric mid-infrared dust rings embedded within the planetary nebula NGC 1514, given JWST/MIRI observations showing that the rings’ emission is dominated by thermal emission from very small grains and lacks PAH, H2, and strong ionic line contributions.

Background

NGC 1514 exhibits a pair of bright, axisymmetric rings that are prominent only in the mid-infrared and appear unique among resolved planetary nebulae surveyed by WISE. JWST/MIRI imaging and spectroscopy reveal that these rings are resolved, filamentary and clumpy structures whose emission in F770W and F1280W is dominated by thermal dust, with negligible contribution from line emission; even at F2550W, [O IV] contributes little within the rings.

Despite measurements of slow radial expansion (~5.5 km s⁻¹) and clear dust-dominated emission, the observations do not provide direct insight into how the rings were formed. The authors compare the morphology with select binary-interaction models but note mismatches in shell placement, age, stellar properties, and the lack of dust treatment in those models.