Abstract
In the coldest regions of molecular clouds, carbon and oxygen are incorporated into icy dust grains. Despite its outsized role in star and planet formation, sequential formation of ice is poorly constrained. Infrared spectroscopy probes ice chemistry, but previous telescopes observed insufficient lines of sight to map a single cloud. Here we present cospatial maps of H2O, CO2 and CO ice over the central region of the Chamaeleon I molecular cloud, using 44 lines of sight observed with the James Webb Space Telescope. Correlations at column densities ten times larger than previous work suggest additional CO2 ice formation in CO ice for the densest lines of sight. This large statistical sampling within a single cloud represents a step change in ice mapping, eliminating averaging over clouds with different intrinsic chemical environments. Mapping opens the door to probing gas–grain exchanges, snow lines and chemical evolution in the densest regions and drawing conclusions on the impact of ice chemistry on wider astrophysics.
Originalsprog | Engelsk |
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Tidsskrift | Nature Astronomy |
ISSN | 2397-3366 |
DOI | |
Status | Accepteret/In press - 2025 |