Photodesorption of ices I: CO, N2 and CO2

Abstract

A longstanding problem in astrochemistry is how molecules can be maintained in the gas phase in dense inter- and circumstellar regions. Photodesorption is a non-thermal desorption mechanism, which may explain the small amounts of observed cold gas in cloud cores and disk mid-planes. This paper aims to determine the UV photodesorption yields and to constrain the photodesorption mechanisms of three astrochemically relevant ices: CO, N2 and CO2. In addition, the possibility of co-desorption in mixed and layered CO:N2 ices is explored. The ice photodesorption is studied experimentally under ultra high vacuum conditions and at 15-60 K using a hydrogen discharge lamp (7-10.5 eV). The ice desorption during irradiation is monitored by reflection absorption infrared spectroscopy of the ice and simultaneous mass spectrometry of the desorbed molecules. Both the UV photodesorption yields per incident photon and the photodesorption mechanisms are molecule specific. CO photodesorbs without dissociation from the surface layer of the ice. N2, which lacks an electronic transition in this wavelength range, has a photodesorption yield that is more than an order of magnitude lower. This yield increases significantly due to co-desorption when N2 is mixed in with or layered on top of CO ice. CO2 photodesorbs through dissociation and subsequent recombination from the top 10 layers of the ice. At low temperatures (15-18 K) the derived photodesorption yields are 2.7x10^-3 and <2x10^-4 molecules photon-1 for pure CO and N2, respectively. The CO2 photodesorption yield is 1.2x10^-3x(1-e^(-X/2.9)) + 1.1x10^-3x(1-e^(-X/4.6)) molecules photon-1, where X is the ice thickness in monolayers and the two parts of the expression represent a CO2 and CO photodesorption pathway.

Accepted by A&A; the new version contains additional figures and text at the referee's request

References in corpus (10)

• The c2d Spitzer spectroscopic survey of ices around low-mass young stellar objects II: CO2
• Photoprocesses in protoplanetary disks
• Desorption rates and sticking coefficients for CO and N2 interstellar ices
• Desorption From Interstellar Ices
• Spatial mapping of ices in the Oph-F core: A direct measurement of CO depletion and the formation of CO2
• Molecular dynamics study of photodissociation of water in crystalline and amorphous ice
• Spitzer IRS Spectra and Envelope Models of Class I Protostars in Taurus
• Investigating grain growth in disks around southern T Tauri stars at millimetre wavelengths
• Detection of HCO2+ toward the Low-Mass Protostar IRAS 04368+2557 in L1527
• Desorption of hot molecules from photon irradiated interstellar ices

Cited by in corpus (148)

• The UMIST database for astrochemistry 2012
• Formation rates of complex organics in UV irradiated CH3OH-rich ices I: Experiments
• Our astrochemical heritage
• A three-phase chemical model of hot cores: the formation of glycine
• Gas and grain chemical composition in cold cores as predicted by the Nautilus 3-phase model
• Chemistry of Dark Clouds: Databases, Networks, and Models
• On the Formation of CO2 and Other Interstellar Ices
• Reaction Networks For Interstellar Chemical Modelling: Improvements and Challenges
• Complex organic molecules in protoplanetary disks
• Astrochemistry and compositions of planetary systems
• Formation of Complex Molecules in Prestellar Cores: a Multilayer Approach
• Chemical Processes in Protoplanetary Disks
• The molecular composition of the planet-forming regions of protoplanetary disks across the luminosity regime
• Chemical evolution of turbulent protoplanetary disks and the Solar nebula
• The Chemistry of Interstellar OH+, H2O+, and H3O+: Inferring the Cosmic Ray Ionization Rates from Observations of Molecular Ions
• Dynamics and Depletion in Thermally Supercritical Starless Cores
• Atom addition reactions in interstellar ice analogues
• Measuring turbulent motion in planet-forming disks with ALMA: A detection around DM Tau and non-detections around MWC 480 and V4046 Sgr
• Photodissociation and X-Ray Dominated Regions
• Herschel Measurements of Molecular Oxygen in Orion
• CO ice photodesorption: A wavelength-dependent study
• Multilayer modeling of porous grain surface chemistry I. The GRAINOBLE model
• Different dust and gas radial extents in protoplanetary disks: consistent models of grain growth and CO emission
• Microscopic simulation of methanol and formaldehyde ice formation in cold dense cores
• Chemical Processes in Protoplanetary Disks II. On the importance of photochemistry and X-ray ionization
• Formation of Complex Organic Molecules in Cold Interstellar Environments through non-diffusive grain-surface and ice-mantle chemistry
• Chemical evolution in the early phases of massive star formation. I
• From Prestellar to Protostellar Cores II. Time Dependence and Deuterium Fractionation
• The chemical history of molecules in circumstellar disks. II. Gas-phase species
• Detection of exocometary CO within the 440 Myr-old Fomalhaut belt: a similar CO+CO${}_2$ ice abundance in exocomets and Solar System comets
• Reprocessing of Ices in Turbulent Protoplanetary Disks: Carbon and Nitrogen Chemistry
• CO destruction in protoplanetary disk midplanes: inside versus outside the CO snow surface
• Binding energies of interstellar molecules on crystalline and amorphous models of water ice by ab-initio calculations
• Impact of low-energy cosmic rays on star formation
• Laboratory H2O:CO2 ice desorption data: entrapment dependencies and its parameterization with an extended three-phase model
• Exocometary gas structure, origin and physical properties around $\beta$ Pictoris through ALMA CO multi-transition observations
• Measurement of Circumstellar Disk Sizes in the Upper Scorpius OB Association with ALMA
• Complex organic molecules in low-mass protostars on solar system scales -- I. Oxygen-bearing species
• Quantification of segregation dynamics in ice mixtures
• Water vapor distribution in protoplanetary disks
• H2CO and N2H+ in Protoplanetary Disks: Evidence for a CO-ice Regulated Chemistry
• Indirect ultraviolet photodesorption from CO:N2 binary ices - an efficient grain-gas process
• New extended deuterium fractionation model: assessment at dense ISM conditions and sensitivity analysis
• The propagation of Lyman-alpha in evolving protoplanetary disks
• Water in Protoplanetary Disks: Deuteration and Turbulent Mixing
• Wavelength-dependent UV photodesorption of pure N2 and O2 ices
• Double DCO+ rings reveal CO ice desorption in the outer disk around IM Lup
• Water deuteration and ortho-to-para nuclear spin ratio of H2 in molecular clouds formed via the accumulation of HI gas
• Molecules with ALMA at Planet-forming Scales (MAPS). VII. Sub-stellar O/H and C/H and super-stellar C/O in planet feeding gas
• Methanol Along the Path from Envelope to Protoplanetary Disc
• The effect of H2O on ice photochemistry
• The IRAM-30m line survey of the Horsehead PDR: IV. Comparative chemistry of H2CO and CH3OH
• Chemistry in Protoplanetary Disks: the gas-phase CO/H2 ratio and the Carbon reservoir
• Chemistry in Disks. IX. Observations and modeling of HCO+ and DCO+ in DM Tau
• H2CO in the Horsehead PDR: Photo-desorption of dust grain ice mantles
• Grain Surface Reactions in Molecular Clouds: The Effect of Cosmic Rays and Quantum Tunneling
• Deep observations of O2 toward a low-mass protostar with Herschel-HIFI
• Complex organic molecules in low-mass protostars on Solar System scales -- II. Nitrogen-bearing species
• Vacuum-UV spectroscopy of interstellar ice analogs. II. Absorption cross-sections of nonpolar ice molecules
• Interstellar Dust Models and Evolutionary Implications
• Three-dimensional off-lattice Monte Carlo kinetics simulations of interstellar grain chemistry and ice structure
• The Impact of Recent Advances in Laboratory Astrophysics on our Understanding of the Cosmos
• Gas-phase CO depletion and N2H+ abundances in starless cores
• Why does ammonia not freeze out in the center of pre-stellar cores?
• Abundant Methanol Masers but no New Evidence for Star Formation in GCM0.253+0.016
• Analytical Formulas of Molecular Ion Abundances and N2H+ Ring in Protoplanetary Disks
• A Unified Microscopic-Macroscopic Monte Carlo Simulation of Gas-Grain Chemistry in Cold Dense Interstellar Clouds
• Porosity measurements of interstellar ice mixtures using optical laser interference and extended effective medium approximations
• Interstellar Simulations Using A Unified Microscopic-Macroscopic Monte Carlo Model with a full Gas-Grain Network including Bulk Diffusion in Ice Mantles
• Molecular line emission from a protoplanetary disk irradiated externally by a nearby massive star
• A survey of H${}_2$O, CO${}_2$ and CO ice features towards background stars and low mass YSOs using AKARI
• Spectrally-resolved UV photodesorption of CH4 in pure and layered ices
• Probing the CO and methanol snow lines in young protostars. Results from the CALYPSO IRAM-PdBI survey
• Unified Microscopic-Macroscopic Monte Carlo Simulations of Complex Organic Molecule Chemistry in Cold Cores
• Laboratory and Computational Studies of Interstellar Ices
• Candidate Water Vapor Lines to Locate the H${}_2$O Snowline through High-Dispersion Spectroscopic Observations I. The Case of a T Tauri Star
• The chemistry of C3 & Carbon Chain Molecules in DR21(OH)
• IR Spectral Fingerprint of Carbon Monoxide in Interstellar Water Ice Models
• Exocomets from a Solar System Perspective
• Hydrodynamics with gas-grain chemistry and radiative transfer: comparing dynamical and static models
• A New and Simple Approach to Determine the Abundance of Hydrogen Molecules on Interstellar Ice Mantles
• Chemical modeling of water deuteration in IRAS16293-2422
• Ro-vibrational CO Detected in the $\beta$~Pictoris Circumstellar Disk
• X-ray induced chemistry of water and related molecules in low-mass protostellar envelopes
• Multiple paths of deuterium fractionation in protoplanetary disks
• First Time-dependent Study of H2 and H3+ Ortho-Para Chemistry in the Diffuse Interstellar Medium: Observations Meet Theoretical Predictions
• Simulations of ice chemistry in cometary nuclei
• CO depletion: a microscopic perspective
• A new study of the chemical structure of the Horsehead nebula: the influence of grain-surface chemistry
• Interplay of gas and ice during cloud evolution
• Methanol maps of low-mass protostellar systems: the Serpens Molecular Core
• Complex organic molecules along the accretion flow in isolated and externally irradiated protoplanetary disks
• Chemical modeling of the L1498 and L1517B prestellar cores: CO and HCO+ depletion
• Subsurface chemistry of mantles of interstellar dust grains in dark molecular cores
• Molecules with ALMA at Planet-forming Scales (MAPS). X. Studying deuteration at high angular resolution toward protoplanetary disks
• Chemical Evolution in a Protoplanetary Disk within Planet Carved Gaps and Dust Rings
• UV photoprocessing of NH3 ice: photon-induced desorption mechanisms
• Beyond the pseudo-time-dependent approach: chemical models of dense core precursors
• Primordial or Secondary? Testing models of debris disk gas with ALMA
• Chemistry in a forming protoplanetary disk: main accretion phase
• The efficiency of photodissociation for molecules in interstellar ices
• The Role of Radiolysis in the Modelling of C${}_2$H${}_4$O${}_2$ Isomers and Dimethyl Ether in Cold Dark Clouds
• The effect of selective desorption mechanisms during interstellar ice formation
• Photodesorption of water ice from dust grains and thermal desorption of cometary ices studied by the INSIDE experiment
• Density and infrared band strength of interstellar carbon monoxide (CO) ice analogues
• Vacuum-UV absorption spectroscopy of interstellar ice analogues. III. Isotopic effects
• The role of OH in the chemical evolution of protoplanetary disks. I. The comet-forming region
• Modeling chemistry during star formation: Water deuteration in dynamic star-forming regions
• A 3D physico-chemical model of a pre-stellar core. I. Environmental and structural impact on the distribution of CH${}_3$OH and $c$-C${}_3$H${}_2$
• ALCHEMI finds a "shocking" carbon footprint in the starburst galaxy NGC~253
• Complex molecules toward low-mass protostars: the Serpens core
• Chemical modeling of the complex organic molecules in the extended region around Sagittarius B2
• Atlas of Cosmic ray-induced astrochemistry
• On The Photodesorption of CO${}_2$ Ice Analogues: The Formation of Atomic C in The Ice and the Effect of The VUV Emission Spectrume
• Accretion and photodesorption of CO ice as a function of the incident angle of deposition
• The Molecular Composition of Shadowed Protosolar Disk Midplanes beyond the Water Snowline
• Physical and Chemical Structure of the Disk and Envelope of the Class 0/I Protostar L1527
• X-ray induced desorption and photochemistry in CO ice
• The effect of multilayer ice chemistry on gas-phase deuteration in starless cores
• Understanding the Formation and Evolution of Interstellar Ices: A Bayesian Approach
• ${}^{13}$CO and ${}^{13}$CO${}_2$ ice mixtures with N${}_2$ in photon energy transfer studies
• On the Diagnostic Power of FIR/Sub-mm SED Fitting in Massive Galactic Molecular Clumps
• Formation of c-C6H5CN ice using the SPACE TIGER experimental setup
• The formation of CO${}_2$ through consumption of gas-phase CO on vacuum-UV irradiated water ice
• Cosmic-ray-induced dissociation and reactions in warm interstellar ices
• Towards detecting methanol emission in low-mass protoplanetary discs with ALMA: The role of non-LTE excitation
• Resonant infrared irradiation of CO and CH3OH interstellar ices
• Chempl: a playable package for modeling interstellar chemistry
• On Modelling Sputtering of Interstellar Grain Ices
• Census of High- and Medium-mass Protostars V. CO Abundance and the Galactic $X_{\text{CO}}$ Factor
• The HIFI spectral survey of AFGL 2591 (CHESS). III. Chemical structure of the protostellar envelope
• Photochemistry of interstellar ice forming Complex Organic Molecules
• Exploring the chemistry induced by energetic processing of the H2-bearing, CO-rich apolar ice layer
• Chemistry During the Gas-rich Stage of Planet Formation
• The role of OH in the chemical evolution of protoplanetary disks II. Gas-rich environments
• Simulation of CH${}_3$OH ice UV photolysis under laboratory conditions
• Towards a better understanding of ice mantle desorption by cosmic rays
• A multigrain-multilayer astrochemical model with variable desorption energy for surface species
• The efficient photodesorption of nitric oxide (NO) ices A laboratory astrophysics study
• Physicochemical models: source-tailored or generic?
• Indirect X-ray photodesorption of 15N2 and 13CO from mixed and layered ices
• Molecules with ALMA at Planet-forming Scales (MAPS) VIII: CO Gap in AS 209--Gas Depletion or Chemical Processing?
• Cosmic-ray induced sputtering of interstellar formaldehyde ices
• Impact of ice growth on the physical and chemical properties of dense cloud cores
• Chemical evolution of a protoplanetary disk
• Flux and fluence effects on the Vacuum-UV photodesorption and photoprocessing of CO${}_2$ ices
• 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
• CO desorption from interstellar icy grains induced by IR excitation of superhydrogenated PAHs