JOYS+ study of solid state ${}^{12}$C/${}^{13}$C isotope ratios in protostellar envelopes: Observations of CO and CO${}_2$ ice with JWST

Abstract

The carbon isotope ratio is a powerful tool for studying the evolution of stellar systems. Recent detections of CO isotopologues in disks and exoplanet atmospheres pointed towards significant fractionation in these systems. In order to understand the evolution of this quantity, it is crucial to trace the isotope abundance from stellar nurseries to planetary systems. During the protostellar stage the multiple vibrational modes of CO${}_2$ and CO ice provide a unique opportunity to examine the carbon isotope ratio in the solid state. Now with the sensitivity of the \textit{James Webb Space Telescope}, these absorption features have become accessible at high S/N in Solar-mass systems. We quantify the ${}^{12}$CO${}_2$/${}^{13}$CO${}_2$ and the ${}^{12}$CO/${}^{13}$CO isotope ratios in 17 class 0/I low mass protostars from the ${}^{12}$CO${}_2$ combination modes (2.70 $\mu$m and 2.77 $\mu$m), the ${}^{12}$CO${}_2$ stretching mode (4.27 $\mu$m), the ${}^{13}$CO${}_2$ stretching mode (4.39 $\mu$m), the ${}^{12}$CO${}_2$ bending mode (15.2 $\mu$m), the ${}^{12}$CO stretching mode (4.67 $\mu$m) and the ${}^{13}$CO stretching mode (4.78 $\mu$m) using JWST observations. We also report a detection of the ${}^{12}$CO overtone mode at 2.35 $\mu$m. The ${}^{12}$CO${}_2$/${}^{13}$CO${}_2$ ratios are in agreement and we find mean ratios of 85 $\pm$ 23, 76 $\pm$ 12 and 97 $\pm$ 17 for the 2.70 $\mu$m, 4.27 $\mu$m and the 15.2 $\mu$m bands, respectively. The main source of uncertainty stem from the error on the band strengths. The ${}^{12}$CO/${}^{13}$CO ratios derived from the 4.67 $\mu$m bands are consistent, albeit elevated with respect to the ${}^{12}$CO${}_2$/${}^{13}$CO${}_2$ ratios and we find a mean ratio of 165 $\pm$ 52. These findings indicate that ices leave the pre-stellar stage with elevated carbon isotope ratios relative to the interstellar medium and that fractionation becomes significant during the later stages.

References in corpus (38)

• Observations of the Icy Universe
• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope I. Overview of the instrument and its capabilities
• The Spitzer ice legacy: Ice evolution from cores to protostars
• The photodissociation and chemistry of CO isotopologues: applications to interstellar clouds and circumstellar disks
• Our astrochemical heritage
• The James Webb Space Telescope Mission
• The ALMA Protostellar Interferometric Line Survey (PILS): First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA
• An Ice Age JWST inventory of dense molecular cloud ices
• The c2d Spitzer spectroscopic survey of ices around low-mass young stellar objects II: CO2
• The VLA Nascent Disk and Multiplicity Survey of Perseus Protostars (VANDAM). II. Multiplicity of Protostars in the Perseus Molecular Cloud
• A 3-5 micron VLT spectroscopic survey of embedded young low mass stars I: Structure of the CO ice
• JWST MIRI flight performance: The Medium-Resolution Spectrometer
• The ALMA-PILS survey: Isotopic composition of oxygen-containing complex organic molecules toward IRAS 16293-2422B
• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope III. Integral-field spectroscopy
• A solar C/O and sub-solar metallicity in a hot Jupiter atmosphere
• Constructing A Flexible Likelihood Function For Spectroscopic Inference
• The 13O-rich atmosphere of a young accreting super-Jupiter
• The Strengths of Near-Infrared Absorption Features Relevant to Interstellar and Planetary Ices
• Deuterium chemistry in protoplanetary disks II The inner 30 AU
• Spitzer Observations of CO2 Ice Towards Field Stars in the Taurus Molecular Cloud
• High Resolution 4.7 um Keck/NIRSPEC Spectra of Protostars. II: Detection of the 13CO Isotope in Icy Grain Mantles
• Nitrogen isotope fractionation in protoplanetary disks
• Infrared spectroscopy of solid CO-CO2 mixtures and layers
• High Resolution 4.7 um Keck/NIRSPEC Spectra of Protostars. I: Ices and Infalling Gas in the Disk of L1489 IRS
• LIDA - The Leiden Ice Database for Astrochemistry
• Further Evidence for Chemical Fractionation from Ultraviolet Observations of Carbon Monoxide
• The 12CO/13CO isotopologue ratio of a young, isolated brown dwarf. Possibly distinct formation pathways of super-Jupiters and brown dwarfs
• The diverse chemistry of protoplanetary disks as revealed by JWST
• Heterogeneity in ${}^{12}$CO/${}^{13}$CO Ratios Toward Solar-Type Young Stellar Objects
• Depletion of heavy nitrogen in the cold gas of star-forming regions
• Multiple nitrogen reservoirs in a protoplanetary disk at the epoch of comet and giant planet formation
• JOYS: JWST Observations of Young protoStars: Outflows and accretion in the high-mass star-forming region IRAS23385+605
• Influence of grain growth on CO2 ice spectroscopic profiles : Modelling for dense cores and disks
• An Introduction to Galactic Chemical Evolution
• The ESO SupJup Survey I: Chemical and isotopic characterisation of the late L-dwarf DENIS J0255-4700 with CRIRES${}^{+}$
• JWST observations of ${}^{13}$CO${}_2$ ice: Tracing the chemical environment and thermal history of ices in protostellar envelopes
• A new method for direct measurement of isotopologue ratios in protoplanetary disks: a case study of the ${}^{12}$CO/${}^{13}$CO ratio in the TW Hya disk
• First detections of H13CO+ and HC15N in the disk around HD 97048: Evidence for a cold gas reservoir in the outer disk

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• JOYS: Linking the molecular ice and gas-phase composition towards the high-mass hot core IRAS 18089-1732
• Molecule-specific diffusion and desorption of interstellar ices on carbonaceous dust
• Detection of CO${}_2$ ice in the planetary nebula NGC 6302
• Mapping Interstellar Ice Inventory toward Class 0 Protostars in Star-forming Region Orion A with JWST Data