JWST multi-instrument mapping reveals layered ices and organics in C/2022 E3 (ZTF)
JWST data show compositional heterogeneity in C/2022 E3 consistent with primordial disk gradients. Multi-instrument GLS improved period detection on radial-velocity analogs but here enabled robust separation of rotational and spatial signals. Evidence remains limited by single-epoch coverage and uncertain nucleus contribution.
The study combined NIRSpec IFU and MIRI LRS data taken in January-February 2023 during the comet's perihelion passage. Researchers constructed spatial-spectral cubes to map emission lines and continuum across the coma and nucleus, applying a multi-instrument GLS periodogram to separate rotational modulation from compositional signals. This approach recovered a 7.3-hour rotation period at higher significance than single-instrument GLS while revealing CO2 enrichment in the sunward hemisphere. Prior ground-based surveys missed these gradients because they lacked the 3-28 micron coverage and spatial resolution needed to separate nucleus and coma contributions. The heterogeneous distribution supports models of comet formation in distinct disk regions before scattering into the Oort cloud. Follow-up observations with ALMA and future missions like Comet Interceptor could test whether similar layering appears in other dynamically new comets.
Martos et al.: A second JWST epoch on C/2022 E3 in 2025 will confirm CO2 asymmetry if the amplitude exceeds 15% at 3-sigma.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2608.20436)
- [2]Supporting Source(https://arxiv.org/abs/2302.10924)