Testing protoplanetary disc evolution with CO fluxes. A proof of concept in Lupus and Upper Sco

Abstract

The Atacama Large Millimeter/submillimeter Array (ALMA) revolutionised our understanding of protoplanetary discs. However, the available data have not given conclusive answers yet on the underlying disc evolution mechanisms (viscosity or MHD winds). Improving upon the current results, mostly based on the analysis of disc sizes, is difficult because larger, deeper and higher angular resolution surveys would be required, which could be prohibitive even for ALMA. In this Letter, we introduce an alternative method to study disc evolution based on ${}^{12}$CO fluxes. In fact, fluxes can be readily collected using less time-consuming, lower resolution observations, while tracing the same disc physico-chemical processes as sizes: assuming that ${}^{12}$CO is optically thick, fluxes scale with the disc surface area. We developed a semi-analytical model to compute ${}^{12}$CO fluxes and benchmarked it against the results of DALI thermochemical models, recovering an agreement within a factor of three. As a proof of concept we compared our models with Lupus and Upper Sco data, taking advantage of the increased samples, by a factor 1.3 (Lupus) and 3.6 (Upper Sco), when studying fluxes instead of sizes. Models and data agree well only if CO depletion is considered. However, the uncertainties on the initial conditions limited our interpretation of the observations. Our new method can be used to design future ad hoc observational strategies to collect better data and give conclusive answers on disc evolution.

arXiv comment10 pages, 9 figures; accepted for publication in A&A Letters. Code and data available at https://github.com/fzagaria/COpops.git

References in corpus (56)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• ALMA Survey of Lupus Protoplanetary Disks I: Dust and Gas Masses
• A Steeper than Linear Disk Mass-Stellar Mass Scaling Relation
• An Old Disk That Can Still Form a Planetary System
• ALMA Survey of Lupus Protoplanetary Disks II: Gas Disk Radii
• The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. A Statistical Characterization of Class 0 and I Protostellar Disks
• ALMA Observations of Circumstellar Disks in the Upper Scorpius OB Association
• The warm gas atmosphere of the HD 100546 disk seen by Herschel (Evidence of a gas-rich, carbon-poor atmosphere?)
• Chemical enrichment of giant planets and discs due to pebble drift
• Survival of molecular gas in cavities of transition disks (I. CO)
• The Ophiuchus DIsc Survey Employing ALMA (ODISEA) - I : project description and continuum images at 28 au resolution
• The Radial Distribution of H2 and CO in TW Hya as Revealed by Resolved ALMA Observations of CO Isotopologues
• 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
• The Coupled Physical Structure of Gas and Dust in the IM Lup Protoplanetary Disk
• Mass measurements in protoplanetary disks from hydrogen deuteride
• The Photoevaporation of Discs Around Young Stars in Massive Clusters
• Characterizing young protostellar disks with the CALYPSO IRAM-PdBI survey: large Class 0 disks are rare
• Determining protoplanetary disk gas masses from CO isotopologues line observations
• 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
• An ALMA Survey of CO isotopologue emission from Protoplanetary Disks in Chamaeleon I
• Unlocking CO Depletion in Protoplanetary Disks I. The Warm Molecular Layer
• Gas vs dust sizes of protoplanetary disks: effects of dust evolution
• Refining the Census of the Upper Scorpius Association with Gaia
• Measurement of Circumstellar Disk Sizes in the Upper Scorpius OB Association with ALMA
• The time evolution of dusty protoplanetary disc radii: observed and physical radii differ
• Constraining Gas-Phase Carbon, Oxygen, and Nitrogen in the IM Lup Protoplanetary Disk
• Bright C2H emission in protoplanetary disks in Lupus: high volatile C/O>1 ratios
• Protoplanetary disc `isochrones' and the evolution of discs in the $\dot{M}-M_{\mathrm{d}}$ plane
• ALMA survey of Class II protoplanetary disks in Corona Australis: a young region with low disk masses
• Tracing water vapor and ice during dust growth
• Chemistry in disks. XI. Sulfur-bearing species as tracers of protoplanetary disk physics and chemistry: the DM Tau case
• Observed sizes of planet-forming disks trace viscous evolution
• First evidence of external disc photoevaporation in a low mass star forming region: the case of IM Lup
• Rapid Evolution of Volatile CO from the Protostellar Disk Stage to the Protoplanetary Disk Stage
• Protoplanetary Disk Sizes and Angular Momentum Transport
• Gas Disk Sizes from CO Line Observations: A Test of Angular Momentum Evolution
• Dust masses of disks around 8 Brown Dwarfs and Very Low-Mass Stars in Upper Sco OB1 and Ophiuchus
• 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
• V1094 Sco: a rare giant multi-ringed disk around a T Tauri star
• Searching for kinematic evidence of Keplerian disks around Class 0 protostars with CALYPSO
• On the secular evolution of the ratio between gas and dust radii in protoplanetary discs
• A ring-like concentration of mm-sized particles in Sz 91
• Demographics of disks around young very low-mass stars and brown dwarfs in Lupus
• A large population study of protoplanetary disks: Explaining the millimeter size-luminosity relation with or without sub-structure
• A Gaia Survey for Young Stars Associated with the Lupus Clouds
• Depletion of gaseous CO in protoplanetary disks by surface-energy-regulated ice formation
• Effect of MHD wind-driven disk evolution on the observed sizes of protoplanetary disks
• Compact Disks: an explanation to faint CO emission in Lupus disks
• An analytic solution to measure the gas size in protoplanetary discs in the viscous self-similar scenario

Cited by in corpus (9)

• Testing external photoevaporation in the $\sigma$-Orionis cluster with spectroscopy and disk mass measurements
• Resolved ALMA observations of water in the inner astronomical units of the HL Tau disk
• The ALMA Survey of Gas Evolution of PROtoplanetary Disks (AGE-PRO): VIII. The impact of external photoevaporation on disk masses and radii in Upper Scorpius
• PRODIGE -- Planet-forming disks in Taurus with NOEMA. I. Overview and first results for 12CO, 13CO, and C18O
• A question of personalities: evolution of viscous and wind-driven protoplanetary discs in the presence of dead zones
• The 12CO Gas Structures of Protoplanetary Disks in the Upper Scorpius Region
• The survivorship bias of protoplanetary disc populations
• Survival of Protoplanetary Disks in Upper Scorpius from Population Synthesis Models with External Photoevaporation
• Observations of highly inclined disks with ALMA. Results from 12CO gas and continuum observations