Vertical CO surfaces as a probe for protoplanetary disk mass and carbon depletion

Abstract

As the sample of mid-inclination disks with measured CO emission surfaces grows, a fundamental unanswered question is how these vertical profiles connect to their host properties. This project aims to relate the vertical extent of protoplanetary disks as traced by ${}^{12}$CO $2-1$ to key stellar and physical parameters. In order to produce a result that is applicable towards an observational analysis, we benchmark our results with ALMA observations of CO emission from nineteen disks. We produce a grid of disk models using the physical-chemical code DALI, for a template T Tauri and Herbig star. Our models use an iterative solver to calculate the hydrostatic equilibrium equations and determine a physically-motivated density structure. Key stellar and disk parameters such as stellar luminosity and temperature, total disk mass, carbon abundance and critical radius are varied to determine their effect on the CO emitting surface. Each vertical profile is fitted by an exponentially tapered power-law and characterized by the $z/r$ value that represents the structure inwards of 80% of the tapering radius. The CO emission surface location is primarily determined by the disk mass ($M_d$) and the level of volatile carbon depletion. T Tauri and Herbig systems show different vertical profiles, with disks around T Tauri stars being more vertically extended. We derive a $z/r$-$M_d$ relationship, which for each stellar type has a degeneracy with the volatile carbon abundance. In order to reconcile total disk mass estimates from the characteristic $z/r$ and the values obtained based on dust continuum analysis, a volatile carbon depletion of 10-100 (with respect to the ISM) is needed for the majority of our sources. Our carbon depletion values are in agreement with previous literature estimates, highlighting the potential of this method to rapidly calculate key disk parameters.

Accepted for publication in A&A

References in corpus (83)

• A computer program for fast non-LTE analysis of interstellar line spectra
• The Disk Substructures at High Angular Resolution Project (DSHARP): I. Motivation, Sample, Calibration, and Overview
• The Mass Dependence Between Protoplanetary Disks and their Stellar Hosts
• Resolved Images of Large Cavities in Protoplanetary Transition Disks
• ALMA Survey of Lupus Protoplanetary Disks I: Dust and Gas Masses
• The photodissociation and chemistry of CO isotopologues: applications to interstellar clouds and circumstellar disks
• The Disk Substructures at High Angular Resolution Project (DSHARP): II. Characteristics of Annular Substructures
• A Steeper than Linear Disk Mass-Stellar Mass Scaling Relation
• Observations of Protoplanetary Disk Structures
• Consistent dust and gas models for protoplanetary disks. I. Disk shape, dust settling, opacities, and PAHs
• ALMA Survey of Lupus Protoplanetary Disks II: Gas Disk Radii
• ALMA Observations of Circumstellar Disks in the Upper Scorpius OB Association
• Weak Turbulence in the HD 163296 Protoplanetary Disk Revealed by ALMA CO Observations
• emcee v3: A Python ensemble sampling toolkit for affine-invariant MCMC
• The warm gas atmosphere of the HD 100546 disk seen by Herschel (Evidence of a gas-rich, carbon-poor atmosphere?)
• Compact Disks in a High Resolution ALMA Survey of Dust Structures in the Taurus Molecular Cloud
• Warm Molecular Layers in Protoplanetary Disks
• A spectroscopic survey of Herbig Ae/Be stars with X-Shooter I: Stellar parameters and accretion rates
• Survival of molecular gas in cavities of transition disks (I. CO)
• The Radial Distribution of H2 and CO in TW Hya as Revealed by Resolved ALMA Observations of CO Isotopologues
• Direct mapping of the temperature and velocity gradients in discs. Imaging the vertical CO snow line around IM Lupi
• Volatile carbon locking and release in protoplanetary disks. A study of TW Hya and HD 100546
• Evidence for a correlation between mass accretion rates onto young stars and the mass of their protoplanetary disks
• Protoplanetary disk masses from CO isotopologues line emission
• Lupus disks with faint CO isotopologues: low gas/dust or large carbon depletion?
• A Significantly Low CO Abundance Toward the TW Hya Protoplanetary Disk: A Path to Active Carbon Chemistry?
• Hydrocarbon emission rings in protoplanetary disks induced by dust evolution
• Observations of edge-on protoplanetary disks with ALMA I. Results from continuum data
• Mass measurements in protoplanetary disks from hydrogen deuteride
• Line Emission from Gas in Optically Thick Dust Disks around Young Stars
• The newborn planet population emerging from ring-like structures in discs
• Determining protoplanetary disk gas masses from CO isotopologues line observations
• Axi-symmetric models of ultraviolet radiative transfer with applications to circumstellar disk chemistry
• Molecules with ALMA at Planet-forming Scales (MAPS) IV: Emission Surfaces and Vertical Distribution of Molecules
• CO Depletion in Protoplanetary Disks: A Unified Picture Combining Physical Sequestration and Chemical Processing
• Transport of CO in Protoplanetary Disks: Consequences of Pebble Formation, Settling, and Radial Drift
• CO destruction in protoplanetary disk midplanes: inside versus outside the CO snow surface
• On the origin of horseshoes in transitional discs
• Systematic Variations of CO Gas Abundance with Radius in Gas-rich Protoplanetary Disks
• The Disk Substructures at High Angular Resolution Project (DSHARP): X. Multiple rings, a misaligned inner disk, and a bright arc in the disk around the T Tauri star HD 143006
• The time evolution of dusty protoplanetary disc radii: observed and physical radii differ
• Study of the properties and spectral energy distributions of the Herbig AeBe stars HD 34282 and HD 141569
• Tracing water vapor and ice during dust growth
• Spiral arms in the proto-planetary disc HD100453 detected with ALMA: evidence for binary-disc interaction and a vertical temperature gradient
• Exploring the Origins of Carbon in Terrestrial Worlds
• CN rings in full protoplanetary disks around young stars as probes of disk structure
• Multi-wavelength continuum sizes of protoplanetary discs: scaling relations and implications for grain growth and radial drift
• Spiral Arms and a Massive Dust Disk with non-Keplerian Kinematics: Possible Evidence for Gravitational Instability in the Disk of Elias 2-27
• Rapid Evolution of Volatile CO from the Protostellar Disk Stage to the Protoplanetary Disk Stage
• The Flying Saucer: Tomography of the thermal and density gas structure of an edge-on protoplanetary disk
• Gas Disk Sizes from CO Line Observations: A Test of Angular Momentum Evolution
• An ALMA Survey of H${}_2$CO in Protoplanetary Disks
• Long Baseline Observations of the HD100546 Protoplanetary Disk with ALMA
• The First Detection of 13C17O in a Protoplanetary Disk: a Robust Tracer of Disk Gas Mass
• Measuring the ratio of the gas and dust emission radii of protoplanetary disks in the Lupus star-forming region
• A dynamical measurement of the disk mass in Elias 2-27
• The TW Hya Rosetta Stone Project III: Resolving the Gaseous Thermal Profile of the Disk
• Directly tracing the vertical stratification of molecules in protoplanetary disks
• Probing Planet Forming Zones with Rare CO Isotopologues
• An evolutionary study of volatile chemistry in protoplanetary disks
• Mass constraints for 15 protoplanetary disks from HD 1-0
• Dynamical mass measurements of two protoplanetary discs
• The Disc Miner II: Revealing Gas substructures and Kinematic signatures from Planet-disc interaction through line profile analysis
• Sulphur monoxide emission tracing an embedded planet in the HD 100546 protoplanetary disk
• A novel way of measuring the gas disk mass of protoplanetary disks using N2H+ and C18O
• The mass and size of Herbig disks as seen by ALMA
• Gas temperature structure across transition disk cavities
• Gas mass tracers in protoplanetary disks: CO is still the best
• ALMA Detection of Dust Trapping around Lagrangian Points in the LkCa 15 Disk
• Rotation curves in protoplanetary disks with thermal stratification
• Mapping Protoplanetary Disk Vertical Structure with CO Isotopologue Line Emission
• Modest dust settling in the IRAS04302+2247 Class I protoplanetary disk
• Investigating the Relative Gas and Small Dust Grain Surface Heights in Protoplanetary Disks
• C${}^{18}$O emission as an effective measure of gas masses of protoplanetary disks
• New Constraints on Protoplanetary Disk Gas Masses in Lupus
• Investigating the asymmetric chemistry in the disk around the young star HD 142527
• Chemical signatures of a warped protoplanetary disc
• Vertically extended and asymmetric CN emission in the Elias 2-27 protoplanetary disk
• ALMA high-resolution observations unveil planet formation shaping molecular emission in the PDS 70 disk
• Radial and vertical constraints on the icy origin of H${}_2$CO in the HD 163296 Protoplanetary Disk
• Tracing Molecular Stratification within an Edge-on Protoplanetary Disk
• A dichotomy in group II Herbig disks: ALMA gas disk height measurements show both shadowed large vertically extended disks and compact flat disks
• Vertical and radial distribution of atomic carbon in HD 163296

Cited by in corpus (2)

• Chemical transformation of CO in evolving protoplanetary discs across stellar masses: a route to C-rich inner regions
• The 12CO Gas Structures of Protoplanetary Disks in the Upper Scorpius Region