HDO Ice Detected toward an Isolated Low-mass Protostar with JWST
Year: 2025
Type: article
Abstract: Water is detected in environments representing every stage of star and solar system formation, but its chemical evolution throughout these stages remains poorly constrained. Deuterium ratios offer a means of probing chemical links between water in different cosmic regions because of their sensitivity to physicochemical conditions. Here, we present the first detection of the 4.1 μm HDO ice feature with JWST toward a low-mass protostar, L1527 IRS, which may eventually grow to a Sun-like mass. We measure an ice HDO/H2O ratio of 4.4 -1.7 +3.7 × 10−3, where the reported error is dominated by uncertainties in continuum definition and ice band strengths. This fraction is similar to the gas HDO/H2O ratios measured in the warm (>100 K) inner cores of other low-mass protostellar envelopes and protoplanetary disks found in comparably isolated star-forming regions. Such a similarity tentatively supports the assumption that water vapor detected in these regions is not significantly altered by gas-phase reactions following ice sublimation. It also supports the hypothesis that pre- and protostellar water ice is largely inherited in a chemically unaltered state by outer protoplanetary disks. However, the fraction is a factor of ∼4–10 times higher than the gas HDO/H2O ratios measured toward comets and low-mass protostars in clustered star-forming regions. This difference may be due to either gas-phase water reprocessing in protostellar envelopes and protoplanetary disks or differences between prestellar conditions of isolated dense cores and the clustered star-forming regions that are more analogous to the environment in which our Sun formed.
Authors: Katerina Slavicinska, Łukasz Tychoniec, María Gabriela Navarro, Ewine F. van Dishoeck, John J. Tobin, Martijn L. van Gelder, Yuan Chen, A. C. Adwin Boogert, W. Blake Drechsler, Henrik Beuther, Alessio Caratti o Garatti, S. Thomas Megeath, Pamela Klaassen, Leslie W. Looney, Patrick J. Kavanagh, Nashanty G. C. Brunken, Patrick Sheehan, William J. Fischer
Institutions: Leiden Observatory, Astronomical Observatory of Rome, National Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, National Radio Astronomy Observatory, University of Hawaiʻi at Mānoa, University of Virginia, Max Planck Institute for Astronomy, Astronomical Observatory of Capodimonte, University of Toledo, Royal Observatory, UK Astronomy Technology Centre, University of Illinois Urbana-Champaign, Dublin Institute For Advanced Studies, Space Telescope Science Institute
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,400
OpenAlex ID: W4411328816