HDO ice detected toward an isolated low-mass protostar with JWST

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 $\mu$m 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/H${}_2$O ratio of 4.4${}_{-1.7}^{+3.7}$$\times$10${}^{-3}$, where the reported error is dominated by uncertainties in continuum definition and ice band strengths. This fraction is similar to the gas HDO/H${}_2$O ratios measured in the warm ($>$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 $\sim$4-10 times higher than the gas HDO/H${}_2$O 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.

arXiv commentAccepted for publication in ApJL. 10 pages, 4 figures, 1 table (+14 pages, 10 figures, 2 tables in appendix)

References in corpus (49)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Observations of the Icy Universe
• The Birth Environment of the Solar System
• The c2d Spitzer Spectroscopic Survey of Ices Around Low-Mass Young Stellar Objects: I. H2O and the 5-8 um Bands
• An Ice Age JWST inventory of dense molecular cloud ices
• Modeling optical properties of cosmic dust grains using a distribution of hollow spheres
• The ancient heritage of water ice in the solar system
• The c2d Spitzer spectroscopic survey of ices around low-mass young stellar objects II: CO2
• A 0.2 solar mass protostar with a Keplerian disk in the very young L1527 IRS system
• Water in star-forming regions with Herschel (WISH): II. Evolution of 557 GHz 110-101 emission in low-mass protostars
• Water in star-forming regions (WISH): Physics and chemistry from clouds to disks as probed by Herschel spectroscopy
• The c2d Spitzer Spectroscopic Survey of Ices Around Low-Mass Young Stellar Objects. IV. NH3 and CH3OH
• Ices in the edge-on disk CRBR 2422.8-3423: Spitzer spectroscopy and Monte Carlo radiative transfer modeling
• Ice and Dust in the Quiescent Medium of Isolated Dense Cores
• A 3D Drizzle Algorithm for JWST and Practical Application to the MIRI Medium Resolution Spectrometer
• Herschel measurements of the D/H and 16O/18O ratios in water in the Oort-cloud comet C/2009 P1 (Garradd)
• Characterizing the nature of embedded young stellar objects through silicate, ice and millimeter observations
• Origin of the 6.85 micron band near young stellar objects: The ammonium ion (NH4+) revisited
• Complex organic molecules in low-mass protostars on solar system scales -- I. Oxygen-bearing species
• Isotopic ratios of H, C, N, O, and S in comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy)
• Terrestrial deuterium-to-hydrogen ratio in water in hyperactive comets
• Water in the envelopes and disks around young high-mass stars
• Modeling the Resolved Disk Around the Class 0 Protostar L1527
• A Herschel Study of D/H in Water in the Jupiter-Family Comet 45P/Honda-Mrkos-Pajdusakova and Prospects for D/H Measurements with CCAT
• The deuterium fractionation of water on solar-system scales in deeply-embedded low-mass protostars
• ALMA Observations of the Protostar L1527 IRS: Probing Details of the Disk and the Envelope Structures
• The 16OH/18OH and OD/OH isotope ratios in comet C/2002 T7 (LINEAR)
• Evolutionary study of complex organic molecules in high-mass star-forming regions
• Search for solid HDO in low-mass protostars
• Complex organic molecules in low-mass protostars on Solar System scales -- II. Nitrogen-bearing species
• Infrared Spectroscopic Survey of the Quiescent Medium of Nearby Clouds: I. Ice Formation and Grain Growth in Lupus
• The abundance of H2O and HDO in Orion KL from Herschel/HIFI
• Investigating Protostellar Accretion-Driven Outflows Across the Mass Spectrum: JWST NIRSpec IFU 3-5~$\mu$m Spectral Mapping of Five Young Protostars
• The Abundance, Ortho/Para Ratio, and Deuteration of Water in the High-Mass Star Forming Region NGC 6334 I
• CoCCoA: Complex Chemistry in hot Cores with ALMA. Selected oxygen-bearing species
• ALMA observations of water deuteration: A physical diagnostic of the formation of protostars
• JOYS+: link between ice and gas of complex organic molecules. Comparing JWST and ALMA data of two low-mass protostars
• Ammonium hydrosulfide (NH4SH) as a potentially significant sulfur sink in interstellar ices
• ALMA observations of doubly deuterated water: Inheritance of water from the prestellar environment
• Early Planet Formation in Embedded Disks (eDisk) III: A first high-resolution view of sub-mm continuum and molecular line emission toward the Class 0 protostar L1527 IRS
• Influence of grain growth on CO2 ice spectroscopic profiles : Modelling for dense cores and disks
• Water deuterium fractionation in the high-mass star-forming region G34.26+0.15 based on Herschel/HIFI data
• JWST observations of ${}^{13}$CO${}_2$ ice: Tracing the chemical environment and thermal history of ices in protostellar envelopes
• The Deuterium Abundance in the Local Interstellar Medium
• JWST detections of amorphous and crystalline HDO ice toward massive protostars
• Methanol deuteration in high-mass protostars
• JOYS+ study of solid state ${}^{12}$C/${}^{13}$C isotope ratios in protostellar envelopes: Observations of CO and CO${}_2$ ice with JWST
• A high HDO/H${}_2$O ratio in the Class I protostar L1551 IRS5

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• Pristine ices in a planet-forming disk revealed by heavy water
• Protostars at Subsolar Metallicity: First Detection of Large Solid-state Complex Organic Molecules in the Large Magellanic Cloud
• The GUAPOS project. VI: the chemical inventory of shocked gas
• JOYS: Linking the molecular ice and gas-phase composition towards the high-mass hot core IRAS 18089-1732
• JOYS: JWST MIRI/MRS spectra of the inner 500 au region of the L1527 IRS bipolar outflow
• Mapping Interstellar Ice Inventory toward Class 0 Protostars in Star-forming Region Orion A with JWST Data