Sulfur depletion in dense clouds and circumstellar regions I. H2S ice abundance and UV-photochemical reactions in the H2O-matrix

Abstract

This work aims to study the unexplained sulfur depletion observed toward dense clouds and protostars. We made simulation experiments of the UV-photoprocessing and sublimation of H2S and H2S:H2O ice in dense clouds and circumstellar regions, using the Interstellar Astrochemistry Chamber (ISAC), a state-of-the-art ultra-high-vacuum setup. The ice was monitored in situ by mid-infrared spectroscopy in transmittance. Temperature-programmed desorption (TPD) of the ice was performed using a quadrupole mass spectrometer (QMS) to detect the volatiles desorbing from the ice. Comparing our laboratory data to infrared observations of protostars we obtained a more accurate upper limit of the abundance of H2S ice toward these objects. We determined the desorption temperature of H2S ice, which depends on the initial H2S:H2O ratio. UV-photoprocessing of H2S:H2O ice led to the formation of several species. Among them, H2S2 was found to photodissociate forming S2 and, by elongation, other species up to S8, which are refractory at room temperature. A large fraction of the missing sulfur in dense clouds and circumstellar regions could thus be polymeric sulfur residing in dust grains.

11 pages, 19 figures

References in corpus (1)

• Sulphur-bearing species in the star forming region L1689N

Cited by in corpus (69)

• On the reservoir of sulphur in dark clouds : chemistry and elemental abundance reconciled
• Modeling Sulfur Depletion in Interstellar Clouds
• Cometary Chemistry and the Origin of Icy Solar System Bodies, the view after Rosetta
• Sulphur chemistry in the L1544 pre-stellar core
• Abundant refractory sulfur in protoplanetary disks
• Gas phase Elemental abundances in Molecular cloudS (GEMS) I. The prototypical dark cloud TMC 1
• Vacuum-UV spectroscopy of interstellar ice analogs. I. Absorption cross-sections of polar-ice molecules
• An infrared measurement of chemical desorption from interstellar ice analogues
• Efficient Production of S${}_8$ in Interstellar Ices: The effects of cosmic ray-driven radiation chemistry and non-diffusive bulk reactions
• A new study of an old sink of sulfur in hot molecular cores: the sulfur residue
• Gas phase Elemental abundances in Molecular cloudS (GEMS). II. On the quest for the sulphur reservoir in molecular clouds: the $H_{2}S$ case
• An Alternative Accurate Tracer of Molecular Clouds: The "$X_{\mathrm{CI}}$-Factor"
• First detection of interstellar S2H
• Gas phase Elemental abundances in Molecular cloudS (GEMS) VII. Sulfur elemental abundance
• Ionization fraction and the enhanced sulfur chemistry in Barnard 1
• Vacuum-UV spectroscopy of interstellar ice analogs. II. Absorption cross-sections of nonpolar ice molecules
• Photoprocessing of H2S on dust grains: building S chains in translucent clouds and comets
• First detection of H${}_2$S in a protoplanetary disk. The dense GG Tau A ring
• Sulfur Ice Astrochemistry: A Review of Laboratory Studies
• The sulfur depletion problem: upper limits on the H2S2, HS2, and S2 gas-phase abundances toward the low-mass warm core IRAS16293-2422
• Detection of interstellar HCS and its metastable isomer HSC: new pieces in the puzzle of sulfur chemistry
• Abundances of sulphur molecules in the Horsehead nebula. First NS+ detection in a photodissociation region
• Polysulfanes on interstellar grains as a possible reservoir of interstellar sulphur
• Modeling accretion shocks at the disk-envelope interface -- Sulfur chemistry
• Gas phase Elemental abundances in Molecular cloudS (GEMS). IV. Observational results and statistical trends
• Bottlenecks to interstellar sulfur chemistry: Sulfur-bearing hydrides in UV-illuminated gas and grains
• Ammonium hydrosulfide (NH4SH) as a potentially significant sulfur sink in interstellar ices
• Tunneling Reaction Kinetics for the Hydrogen Abstraction Reaction H + H${}_2$S -> H${}_2$ + HS in the Interstellar Medium
• Thermal and energetic processing of astrophysical ice analogues rich in SO${}_2$
• Sulfur Chemistry in L1157-B1
• The Perseus ALMA Chemical Survey (PEACHES). III. Sulfur-bearing species tracing accretion and ejection processes in young protostars
• JWST detections of amorphous and crystalline HDO ice toward massive protostars
• Gas-phase Elemental abundances in Molecular cloudS (GEMS) III. Unlocking the CS chemistry: the CS+O reaction
• Quantifying the chemical desorption of H${}_2$S and PH${}_3$ from amorphous water ice surfaces
• X-ray extinction from interstellar dust: Prospects of observing carbon, sulfur and other trace elements
• Formation of S-bearing complex organic molecules in interstellar clouds via ice reactions with C2H2, HS, and atomic H
• Submillimeter spectroscopy and astronomical searches of vinyl mercaptan, C${}_2$H${}_3$SH
• Gas phase Elemental abundances in Molecular cloudS (GEMS) VI. A sulphur journey across star-forming regions: study of thioformaldehyde emission
• AB Aur, a Rosetta stone for studies of planet formation (II): H${}_2$S detection and sulfur budget
• Energetic Electron Irradiations of Amorphous and Crystalline Sulphur-Bearing Astrochemical Ices
• Evidence for sulfur-bearing species on Callisto's leading hemisphere: Sourced from Jupiter's irregular satellites or Io?
• Successive H-atom addition to solid OCS on compact amorphous solid water
• Sulfur-bearing species in molecular clouds
• High-Resolution SOFIA/EXES Spectroscopy of ${\mathrm{SO}}_2$ Gas in the Massive Young Stellar Object MonR2 IRS3: Implications for the Sulfur Budget
• H${}_2$S observations in young stellar disks in Taurus
• Accurate millimetre and submillimetre rest frequencies for $cis$- and $trans$-dithioformic acid, HCSSH
• Theoretical modelling of the adsorption of neutral and charged sulphur-bearing species on to olivine nanoclusters
• First images of phosphorus molecules towards a proto-Solar analog
• ALMA ACA study of the H${}_2$S/OCS ratio in low-mass protostars
• Probing the kinematics and chemistry of the hot core Mon R 2 IRS 3 using ALMA observations
• Stability of sulphur dimers S2 in cometary ices
• Formation of carbonyl sulfide (OCS) via SH radicals in interstellar CO-rich ice under dense cloud conditions
• Photochemistry of interstellar ice forming Complex Organic Molecules
• An ALCHEMI inspection of sulphur-bearing species towards the central molecular zone of NGC 253
• Chemical variations across the TMC-1 boundary: molecular tracers from translucent phase to dense phase
• Binding Energies and Vibrational Spectral Features of S${}_n$ Species on Amorphous Water-ice Mantles: A Quantum Mechanical Study
• Ice origins of OCS and chemistry of CS2-bearing ice mantles
• H2S ice sublimation dynamics: experimentally constrained binding energies, entrapment efficiencies, and snowlines
• XRISM insights for interstellar Sulfur
• First detection of HS2 in a cold dark cloud
• PRODIGE VI -- Envelope to Disk with NOEMA: VI. The Missing Sulfur Problem
• The sulfur plume in the Horsehead nebula: New detections of S${}_2$H, SH${}^{+}$, and CO${}^{+}$
• Gas phase Elemental abundances in Molecular cloudS (GEMS). IX. Deuterated compounds of H2S in starless cores
• A quest for sulfur-bearing refractory species. Identification of CaS in the interstellar medium
• Formation of thiocarbonic acid (H${}_2$CS${}_3$) -- the sulfur counterpart of carbonic acid (H${}_2$CO${}_3$) - in interstellar analog ices
• Gas phase Elemental abundances in Molecular cloudS (GEMS) VIII. Unlocking the CS chemistry: the CH + S$\to$ CS + H and C${}_2$ + S$\to$ CS + C reactions
• Observational studies on S-bearing molecules in massive star forming regions
• Fine-tuning the complex organic molecule formation: sulfur and CO ice as regulators of surface chemistry
• Modeling the UV-photon irradiation of CS${}_2$-bearing ices in the laboratory with the pyRate gas-grain astrochemical code. New insights into the missing sulfur problem