Mapping of interstellar ices with JWST in protostellar envelopes: Spatial variations of $^{13}$CO$_2$, $^{12}$CO$_2$, CO, OCN$^-$ and H$_2$O ice
Year: 2026
Type: preprint
Abstract: The composition of planets and their atmospheres is largely determined by the formation environment of the planet. This environment is pre-determined during early stages when the protostar is still forming. Charting the structure of protostellar envelopes is therefore crucial for understanding how the chemistry is linked to the physical processes occurring in stellar nurseries. We use JWST NIRSpec IFU observations to extract spectra at every pixel in the IFU and map the distribution of $^{13}$CO$_2$,$^{12}$CO$_2$, CO, OCN$^-$ and H$_2$O ice. The 13CO2 ice feature, a known thermal tracer, is also used to identify high-temperature regions where the ices are thermally processed. The findings show that the distribution of ices in both L1527 and IRAS 20126+4104 is not uniform, with both envelopes showing localized temperature zones and substructures. In L1527, CO$_2$ ice segregation and OCN$^-$ enhancement with respect to CO$_2$ are observed in the warm central disk region close to the protostar. In IRAS 20126+4104, the warm temperature zones are observed mostly towards the shocked region in the NW outflow where dense material is interacting with the precessing jet as well as close to the central source. The CO$_2$ ice is segregated at these locations and we observe sublimation of CO ice. In addition, crystalline H$_2$O ice is detected at a few locations in the envelope. In both low mass and high mass protostar the findings indicate that the distribution of ices and their structure are linked to the temperature structure of the envelopes. The envelope of IRAS 20126 shows a more complex structure, where interacting material results in localized regions of high temperatures and denser regions that harbor cooler ices. L1527 in contrast appears to be a more structured system with heated warm ices observed mostly towards the central disk regions.
Source: arXiv (Cornell University)
Institutions: Leiden University, Max Planck Institute for Extraterrestrial Physics, Leiden Observatory, University of Hawaiʻi at Mānoa, University of Cambridge, Center for Astrophysics Harvard & Smithsonian, Max Planck Institute for Astronomy, Astronomical Observatory of Capodimonte, National Institute for Astrophysics, University of Toledo, Tata Institute of Fundamental Research, RIKEN, The University of Texas at Austin
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Aeronautics and Space Administration, Space Telescope Science Institute, University of Warwick, European Commission, Enterprise Ireland, Danmarks Grundforskningsfond, Swedish National Space Agency, Belgian Federal Science Policy Office, Centre National d’Etudes Spatiales, Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Science and Technology Facilities Council
OpenAlex ID: W7220898595