Different dust and gas radial extents in protoplanetary disks: consistent models of grain growth and CO emission

Abstract

ALMA observations of protoplanetary disks confirm earlier indications that there is a clear difference between the dust and gas radial extents. The origin of this difference is still debated, with both radial drift of the dust and optical depth effects suggested in the literature. In this work, the feedback of realistic dust particle distributions onto the gas chemistry and molecular emissivity is investigated, with a particular focus on CO isotopologues. The radial dust grain size distribution is determined using dust evolution models that include growth, fragmentation and radial drift. A new version of the code DALI is used to take into account how dust surface area and density influence the disk thermal structure, molecular abundances and excitation. The difference of dust and gas radial sizes is largely due to differences in the optical depth of CO lines and millimeter continuum, without the need to invoke radial drift. The effect of radial drift is primarily visible in the sharp outer edge of the continuum intensity profile. The gas outer radius probed by ${}^{12}$CO emission can easily differ by a factor of $\sim 2$ between the models for a turbulent $\alpha$ ranging between typical values. Grain growth and settling concur in thermally decoupling the gas and dust components, due to the low collision rate with large grains. As a result, the gas can be much colder than the dust at intermediate heights, reducing the CO excitation and emission, especially for low turbulence values. Also, due to disk mid-plane shadowing, a second CO thermal desorption (rather than photodesorption) front can occur in the warmer outer mid-plane disk. The models are compared to ALMA observations of HD 163296 as a test case. In order to reproduce the observed CO snowline of the system, a binding energy for CO typical of ice mixtures needs to be used rather than the lower pure CO value.

arXiv comment26 pages, 25 figures, accepted for publication in A&A, abstract shortened to fit arXiv requirements

References in corpus (113)

• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• Protoplanetary Disks and Their Evolution
• First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
• Circumstellar Dust Disks in Taurus-Auriga: The Submillimeter Perspective
• A simple model for the evolution of the dust population in protoplanetary disks
• Passive irradiated circumstellar disks with an inner hole
• Coagulation, fragmentation and radial motion of solid particles in protoplanetary disks
• Protoplanetary Disk Structures in Ophiuchus
• Gas- and dust evolution in protoplanetary disks
• Scattering by Interstellar Dust Grains: Optical and Ultraviolet
• Particle Stirring in Turbulent Gas Disks: Including Orbital Oscillations
• Ringed Substructure and a Gap at 1 AU in the Nearest Protoplanetary Disk
• Dynamics of Protoplanetary Disks
• Closed-form expressions for particle relative velocities induced by turbulence
• Photoevaporation of Circumstellar Disks due to External FUV Radiation in Stellar Aggregates
• The effect of dust settling on the appearance of protoplanetary disks
• Effects of Dust Growth and Settling in T Tauri Disks
• Dust Properties of Protoplanetary Disks in the Taurus-Auriga Star Forming Region from Millimeter Wavelengths
• Radiation thermo-chemical models of protoplanetary disks I. Hydrostatic disk structure and inner rim
• Water, O2 and Ice in Molecular Clouds
• Consistent dust and gas models for protoplanetary disks. I. Disk shape, dust settling, opacities, and PAHs
• A Submillimeter View of Circumstellar Dust Disks in $\rho$ Ophiuchus
• The stickiness of micrometer-sized water-ice particles
• A dual-frequency sub-arcsecond study of proto-planetary disks at mm wavelengths: First evidence for radial variations of the dust properties
• Photodesorption of Ices II: H2O and D2O
• Dust Evolution and the Formation of Planetesimals
• Photodesorption of ices I: CO, N2 and CO2
• Weak Turbulence in the HD 163296 Protoplanetary Disk Revealed by ALMA CO Observations
• The TW Hya Disk at 870 microns: Comparison of CO and Dust Radial Structures
• A Parametric Modeling Approach to Measuring the Gas Masses of Circumstellar Disks
• The warm gas atmosphere of the HD 100546 disk seen by Herschel (Evidence of a gas-rich, carbon-poor atmosphere?)
• Dust size distributions in coagulation/fragmentation equilibrium: Numerical solutions and analytical fits
• Constraints on the Radial Variation of Grain Growth in the AS 209 Circumstellar Disk
• Dust grain growth in rho-Ophiuchi protoplanetary disks
• Resolved gas cavities in transitional disks inferred from CO isotopologues with ALMA
• Survival of molecular gas in cavities of transition disks (I. CO)
• The chemical history of molecules in circumstellar disks. I. Ices
• Molecular hydrogen formation in the interstellar medium
• A Spatially Resolved Vertical Temperature Gradient in the HD 163296 Disk
• Large grains in the disk of CQ Tau
• The Radial Distribution of H2 and CO in TW Hya as Revealed by Resolved ALMA Observations of CO Isotopologues
• Desorption rates and sticking coefficients for CO and N2 interstellar ices
• Volatile carbon locking and release in protoplanetary disks. A study of TW Hya and HD 100546
• Lupus disks with faint CO isotopologues: low gas/dust or large carbon depletion?
• Protoplanetary disk masses from CO isotopologues line emission
• A multi-wavelength analysis for interferometric (sub-)mm observations of protoplanetary disks: radial constraints on the dust properties and the disk structure
• Dust settling in local simulations of turbulent protoplanetary disks
• A search for evolved dust in Herbig Ae stars
• Unveiling the gas and dust disk structure in HD 163296 using ALMA observations
• Hydrocarbon emission rings in protoplanetary disks induced by dust evolution
• The Coupled Physical Structure of Gas and Dust in the IM Lup Protoplanetary Disk
• Mass measurements in protoplanetary disks from hydrogen deuteride
• Gas density drops inside dust cavities of transitional disks around young stars observed with ALMA
• Measuring Turbulence in TW Hya with ALMA: Methods and Limitations
• Challenges in Planet Formation
• Molecular Hydrogen Emission from Protoplanetary Disks II. Effects of X-ray Irradiation and Dust Evolution
• Gas and Dust Emission at the Outer Edge of Protoplanetary Disks
• The Impact of Dust Evolution and Photoevaporation on Disk Dispersal
• Mie Scattering by Ensembles of Particles with Very Large Size Parameters
• Empirical Constraints on Turbulence in Protoplanetary Accretion Disks
• On the Outer Edges of Protoplanetary Dust Disks
• Chemical Imaging of the CO Snow Line in the HD 163296 Disk
• Determining protoplanetary disk gas masses from CO isotopologues line observations
• Gas structure inside dust cavities of transition disks: Oph IRS 48 observed by ALMA
• The chemical history of molecules in circumstellar disks. II. Gas-phase species
• External photoevaporation of protoplanetary discs in sparse stellar groups: the impact of dust growth
• Millimeter imaging of HD 163296: probing the disk structure and kinematics
• Chemistry of a protoplanetary disk with grain settling and Lyman alpha radiation
• Global MHD simulations of stratified and turbulent protoplanetary discs. II. Dust settling
• On the structure of the transition disk around TW Hya
• Thermal desorption of circumstellar and cometary ice analogs
• The gas temperature in flaring disks around pre-main sequence stars
• C/O and Snowline Locations in Protoplanetary Disks: The Effect of Radial Drift and Viscous Gas Accretion
• Grain Growth in the Circumstellar Disks of the Young Stars CY Tau and DoAr 25
• ALMA imaging of the CO snowline of the HD 163296 disk with DCO+
• CO and N${}_2$ desorption energies from water ice
• Probing Pre-Protosellar Cores with Formaldehyde
• Robustness of N2H+ as tracer of the CO snowline
• Resolving the Far-IR Line Deficit: Photoelectric Heating and Far-IR Line Cooling in NGC 1097 and NGC 4559
• A Gap with a Deficit of Large Grains in the protoplanetary disk around TW Hya
• Investigating grain growth in disks around southern T Tauri stars at millimetre wavelengths
• Dust Evolution Can Produce Scattered Light Gaps in Protoplanetary Disks
• A break in the gas and dust surface density of the disc around the T Tauri star IM Lup
• Double DCO+ rings reveal CO ice desorption in the outer disk around IM Lup
• A tidal encounter caught in the act: modelling a star-disc fly-by in the young RW Aurigae system
• Tracing water vapor and ice during dust growth
• Observations of Solids in Protoplanetary Disks
• Encounter-Triggered Disc Mass Loss in the ONC
• Gas modelling in the disc of HD 163296
• Protoplanetary disc evolution affected by star-disc interactions in young stellar clusters
• Chemistry and line emission from evolving Herbig Ae disks
• Chemical Modelling of Young Stellar Objects, I. Method and Benchmarks
• Multiple Carbon monoxide Snow-lines in Disks Sculpted by Radial Drift
• Strong effect of the cluster environment on the size of protoplanetary discs?
• Faint disks around classical T Tauri stars: small but dense enough to form planets?
• A Spitzer Survey of Protoplanetary Disk Dust in the Young Serpens Cloud: How do Dust Characteristics Evolve with Time?
• The Role of Ice Compositions for Snowlines and the C/N/O Ratios in Active Disks
• Evidence for a CO desorption front in the outer AS 209 disk
• Impact of grain evolution on the chemical structure of protoplanetary disks
• Ro-vibrational excitation of an organic molecule (HCN) in protoplanetary disks
• Stacking Spectra in Protoplanetary Disks: Detecting Intensity Profiles from Hidden Molecular Lines in HD 163296
• Accretion variability of Herbig Ae/Be stars observed by X-Shooter. HD 31648 and HD 163296
• Jets, accretion, coronae and all that: The enigmatic X-rays from the Herbig star HD 163296
• A Surface Density Perturbation in the TW Hydrae Disk at 95 au Traced by Molecular Emission
• Gas Gaps in the Protoplanetary Disk around the Young Protostar HL Tau
• Grain growth across protoplanetary discs: 10-micron silicate feature versus millimetre slope
• Grand challenges in protoplanetary disc modelling
• Dust properties across the CO snowline in the HD 163296 disk from ALMA and VLA observations
• Probing the 2D temperature structure of protoplanetary disks with Herschel observations of high-J CO lines
• Determining the mid-plane conditions of circumstellar discs using gas and dust modelling: a study of HD 163296
• Measuring protoplanetary disk gas surface density profiles with ALMA
• Photochemical-dynamical models of externally FUV irradiated protoplanetary discs
• Dust crystallinity in protoplanetary disks: the effect of diffusion/viscosity ratio

Cited by in corpus (114)

• The Disk Substructures at High Angular Resolution Project (DSHARP): I. Motivation, Sample, Calibration, and Overview
• Gaps and Rings in an ALMA Survey of Disks in the Taurus Star-forming Region
• Observations of Protoplanetary Disk Structures
• ALMA Survey of Lupus Protoplanetary Disks II: Gas Disk Radii
• Observations of edge-on protoplanetary disks with ALMA I. Results from continuum data
• Protoplanetary disc truncation mechanisms in stellar clusters: comparing external photoevaporation and tidal encounters
• Molecular abundances and C/O ratios in chemically evolving planet-forming disk midplanes
• Protoplanetary disk rings and gaps across ages and luminosities
• CO and dust properties in the TW Hya disk from high-resolution ALMA observations
• Molecules with ALMA at Planet-forming Scales (MAPS) IV: Emission Surfaces and Vertical Distribution of Molecules
• Transport of CO in Protoplanetary Disks: Consequences of Pebble Formation, Settling, and Radial Drift
• New insights into the nature of transition disks from a complete disk survey of the Lupus star forming region
• The FRIED grid of mass loss rates for externally irradiated protoplanetary discs
• Signatures of broken protoplanetary discs in scattered light and in sub-millimetre observations
• Gas vs dust sizes of protoplanetary disks: effects of dust evolution
• Observational constraints on dust disk sizes in tidally truncated protoplanetary disks in multiple systems in the Taurus region
• Measurement of Circumstellar Disk Sizes in the Upper Scorpius OB Association with ALMA
• Rings and gaps in the disc around Elias 24 revealed by ALMA
• Protoplanetary Disks in $\rho$ Ophiuchus as Seen From ALMA
• The time evolution of dusty protoplanetary disc radii: observed and physical radii differ
• A circumbinary protoplanetary disc in a polar configuration
• The circumstellar disk HD169142: gas, dust and planets acting in concert?
• Consistent dust and gas models for protoplanetary disks III. Models for selected objects from the FP7 DIANA project
• Methanol and its relation to the water snowline in the disk around the young outbursting star V883 Ori
• Low dust emissivities and radial variations in the envelopes of Class 0 protostars: a signature of early grain growth?
• Spiral Arms in Disks: Planets or Gravitational Instability?
• External photoevaporation of circumstellar disks constrains the timescale for planet formation
• High gas/dust size ratio indicating efficient radial drift in the mm-faint CX Tau disk
• Observed sizes of planet-forming disks trace viscous evolution
• CN rings in full protoplanetary disks around young stars as probes of disk structure
• Inferring giant planets from ALMA millimeter continuum and line observations in (transition) disks
• Annular substructures in the transition disks around LkCa 15 and J1610
• Gas Disk Sizes from CO Line Observations: A Test of Angular Momentum Evolution
• Gas and multi-species dust dynamics in viscous protoplanetary discs: the importance of the dust back-reaction
• Spatial segregation of dust grains in transition disks. SPHERE observations of 2MASS J16083070-3828268 and RXJ1852.3-3700
• The chemical inventory of the planet-hosting disk PDS 70
• Measuring the ratio of the gas and dust emission radii of protoplanetary disks in the Lupus star-forming region
• A dust and gas cavity in the disc around CQ Tau revealed by ALMA
• DCO${}^{+}$, DCN and N${}_2$D${}^{+}$ reveal three different deuteration regimes in the disk around the Herbig Ae star HD163296
• On the secular evolution of the ratio between gas and dust radii in protoplanetary discs
• Rings and gaps in protoplanetary disks: planets or snowlines?
• A highly non-Keplerian protoplanetary disc: Spiral structure in the gas disc of CQ Tau
• Protoplanetary Disks in the Orion Nebula Cluster: Gas Disk Morphologies and Kinematics as seen with ALMA
• Gas temperature structure across transition disk cavities
• Kinematics and brightness temperatures of transition discs -- A survey of gas substructures as seen with ALMA
• ALMA chemical survey of disk-outflow sources in Taurus (ALMA-DOT) V: Sample, overview, and demography of disk molecular emission
• A 80 au cavity in the disk around HD 34282
• Disk structure around the Class I protostar L1489 IRS revealed by ALMA: a warped disk system
• Probing midplane CO abundance and gas temperature with DCO${}^{+}$ in the protoplanetary disk around HD 169142
• Interpreting high spatial resolution line observations of planet-forming disks with gaps and rings -- The case of HD 163296
• AB Aur, a Rosetta stone for studies of planet formation (I): chemical study of a planet-forming disk
• Early Planet Formation in Embedded Disks (eDisk). IV. The Ringed and Warped Structure of the Disk around the Class I Protostar L1489 IRS
• X-ray radiative transfer in protoplanetary disks - The role of dust and X-ray background fields
• Rotation curves in protoplanetary disks with thermal stratification
• The ALMA Lupus protoplanetary disk survey: evidence for compact gas disks and molecular rings from CN
• Herbig Stars: A Quarter Century of Progress
• Formation and evolution of a protoplanetary disk: combining observations, simulations and cosmochemical constraints
• Observational constraints on disc sizes in protoplanetary discs in multiple systems in the Taurus region. II. Gas disc sizes
• Investigating the Relative Gas and Small Dust Grain Surface Heights in Protoplanetary Disks
• Destruction of refractory carbon grains drives the final stage of proto-planetary disk chemistry
• Tracing pebble drift and trapping using radial carbon depletion profiles in protoplanetary disks
• ALMA chemical survey of disk-outflow sources in Taurus (ALMA-DOT): I. CO, CS, CN, and H2CO around DG Tau B
• ALMA detects a radial disk wind in DG Tau
• Gravitoviscous protoplanetary disks with a dust component. III. Evolution of gas, dust, and pebbles
• Constraining the radial drift of millimeter-sized grains in the protoplanetary disks in Lupus
• 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
• Effect of MHD wind-driven disk evolution on the observed sizes of protoplanetary disks
• The Anatomy of an Unusual Edge-on Protoplanetary Disk. II. Gas temperature and a warm outer region
• Asymmetric mid-plane gas in ALMA images of HD~100546
• ISPY-NACO Imaging Survey for Planets around Young stars. The demographics of forming planets embedded in protoplanetary disks
• Investigating the asymmetric chemistry in the disk around the young star HD 142527
• MINDS. JWST-MIRI reveals a peculiar CO${}_2$-rich chemistry in the drift-dominated disk CX Tau
• Self-consistent modelling of the dust component in protoplanetary and circumplanetary disks: the case of PDS 70
• Establishing Dust Rings and Forming Planets Within Them
• Early Planet Formation in Embedded Disks (eDisk) V: Possible Annular Substructure in a Circumstellar Disk in the Ced110 IRS4 System
• Chemical modeling of Orion Nebula Cluster disks: evidence for massive, compact gas disks with ISM-like gas-to-dust ratios
• Observing the gas component of circumplanetary disks around wide-orbit planet-mass companions in the (sub)mm regime
• Exploring HNC and HCN line emission as probes of the protoplanetary disk temperature
• Probing the protoplanetary disk gas surface density distribution with ${}^{13}$CO emission
• High resolution observations of molecular emission lines toward the CI Tau proto-planetary disc: planet-carved gaps or shadowing?
• Formation of Planetary Populations II: Effects of Initial Disk Size & Radial Dust Drift
• exoALMA. XVII. Characterizing the Gas Dynamics around Dust Asymmetries
• An analytic solution to measure the gas size in protoplanetary discs in the viscous self-similar scenario
• Gravitoviscous Protoplanetary Discs with a Dust Component. IV. Disc Outer Edges, Spectral Indices, and Opacity Gaps
• On dust evolution in planet-forming discs in binary systems. II -- Comparison with Taurus and $\rho$ Ophiuchus (sub-)millimetre observations: discs in binaries have small dust sizes
• First detections of H13CO+ and HC15N in the disk around HD 97048: Evidence for a cold gas reservoir in the outer disk
• High-resolution ALMA observations of compact discs in the wide-binary system Sz 65 and Sz 66
• A brief overview of planet formation
• CO isotopolog line fluxes of viscously evolving disks: cold CO conversion insufficient to explain observed low fluxes
• Architecture of planetary systems predicted from protoplanetary disks observed with ALMA I: mass of the possible planets embedded in the dust gap
• Exploring DCO${}^{+}$ as a tracer of thermal inversion in the disk around the Herbig Ae star HD163296
• Chemistry During the Gas-rich Stage of Planet Formation
• No impact of core-scale magnetic field, turbulence, or velocity gradient on sizes of protostellar disks in Orion A
• An APEX search for carbon emission from NGC 1977 proplyds
• Multi-frequency analysis of the ALMA and VLA high resolution continuum observations of the substructured disc around CI Tau. Preference for sub-mm-sized low-porosity amorphous carbon grains
• Constraints on the gas-phase C/O ratio of DR Tau's outer disk from CS, SO, and C${}_2$H observations
• Searching for wide-orbit gravitational instability protoplanets with ALMA in the dust continuum
• Multiple Rings and Asymmetric Structures in the Disk of SR 21
• The effect of stellar evolution on dispersal of protoplanetary disks: Disk fraction in star-forming regions
• Confirmation of a ring structure in the disk around MP Mus (PDS 66) with ALMA Band 7 observations
• Re-visiting the case of R Mon: Is CO removed at R<20 au?
• Molecules with ALMA at Planet-forming Scales (MAPS) III: Characteristics of Radial Chemical Substructures
• The extremely truncated circumstellar disc of V410 X-ray 1: a precursor to TRAPPIST-1?
• Gaps and Rings: A Near-Universal Trait of Extended Protoplanetary Discs
• Compact CO emission and no evidence of radial drift. ALMA observations of the faintest planet-forming disks in Lupus
• JWST Imaging of Edge-on Protoplanetary Disks. V. Flux Ratio Reversal and Disk-edge Structure in the Flying Saucer
• Dispersal of protoplanetary discs: How stellar properties and the local environment determine the pathway of evolution
• Modelling the secular evolution of proto-planetary disc dust sizes -- A comparison between the viscous and magnetic wind case
• CO Line Emission Surfaces and Vertical Structure in Mid-Inclination Protoplanetary Disks
• Protoplanetary Disk Chemistry
• Global Non-ideal Magnetohydrodynamic Simulations of Protoplanetary Disks with Outer Truncation
• Gas and Dust Shadows in the TW Hydrae Disk
• Observations of highly inclined disks with ALMA. Results from 12CO gas and continuum observations