Gas density drops inside dust cavities of transitional disks around young stars observed with ALMA

Abstract

Transitional disks with large dust cavities are important laboratories to study planet formation and disk evolution. Cold gas may still be present inside these cavities, but the quantification of this gas is challenging. The gas content is important to constrain the origin of the dust cavity. We use Atacama Large Millimeter/submillimeter Array (ALMA) observations of 12CO 6--5 and 690 GHz (Band 9) continuum of five well-studied transitional disks. In addition, we analyze previously published Band 7 observations of a disk in 12CO 3--2 line and 345 GHz continuum. The observations are used to set constraints on the gas and dust surface density profiles, in particular the drop delta-gas of the gas density inside the dust cavity. The physical-chemical modeling code DALI is used to analyze the gas and dust images simultaneously. We model SR21, HD135344B, LkCa15, SR24S and RXJ1615-3255 (Band 9) and J1604-2130 (Band 7). The SED and continuum visibility curve constrain the dust surface density. Subsequently, the same model is used to calculate the 12CO emission, which is compared with the observations through spectra and intensity cuts. The amount of gas inside the cavity is quantified by varying the delta-gas parameter. Model fits to the dust and gas indicate that gas is still present inside the dust cavity for all disks but at a reduced level. The gas surface density drops inside the cavity by at least a factor 10, whereas the dust density drops by at least a factor 1000. Disk masses are comparable with previous estimates from the literature, cavity radii are found to be smaller than in the 345 GHz SubMillimeter Array (SMA) data. The derived gas surface density profiles suggest clearing of the cavity by one or more companions in all cases, trapping the millimeter-sized dust at the edge of the cavity.

Accepted by A&A

References in corpus (20)

• Coagulation, fragmentation and radial motion of solid particles in protoplanetary disks
• Ring shaped dust accumulation in transition disks
• Accretion in the Rho-Oph pre-main sequence stars
• Spectro-astrometric imaging of molecular gas within protoplanetary disk gaps
• Photoprocesses in protoplanetary disks
• Demographics of Transition Objects
• LkH$\alpha$ 330: Evidence for dust clearing through resolved submillimeter imaging
• Line Emission from Gas in Optically Thick Dust Disks around Young Stars
• ALMA hints at the presence of two companions in the disk around HD 100546
• The nature of the Class I population in Ophiuchus as revealed through gas and dust mapping
• Tracing the inner edge of the disk around HD 100546 with Ro-vibrational CO Emission Lines
• Gas and dust structures in protoplanetary disks hosting multiple planets
• CO gas inside the protoplanetary disk cavity in HD 142527: disk structure from ALMA
• Direct Imaging of Bridged Twin Protoplanetary Disks in a Young Multiple Star
• Comparison of the dust and gas radial structure in the transition disk [PZ99] J160421.7-213028
• An ALMA Continuum Survey of Circumstellar Disks in the Upper Scorpius OB Association
• Modeling the gas-phase chemistry of the transitional disk around HD 141569A
• Constraining the structure of the transition disk HD 135344B (SAO 206462) by simultaneous modeling of multiwavelength gas and dust observations
• Rossby wave instability does not require sharp resistivity gradients
• Gas inside the 97 au cavity around the transition disk Sz\,91

Cited by in corpus (64)

• Multiple Disk Gaps and Rings Generated by a Single Super-Earth
• The Coupled Physical Structure of Gas and Dust in the IM Lup Protoplanetary Disk
• Molecules with ALMA at Planet-forming Scales (MAPS) V: CO gas distributions
• Water in star-forming regions (WISH): Physics and chemistry from clouds to disks as probed by Herschel spectroscopy
• Highly structured disk around the planet host PDS 70 revealed by high-angular resolution observations with ALMA
• Different dust and gas radial extents in protoplanetary disks: consistent models of grain growth and CO emission
• CO and dust properties in the TW Hya disk from high-resolution ALMA observations
• Protoplanetary disk rings and gaps across ages and luminosities
• On the formation of multiple concentric rings and gaps in protoplanetary disks
• An ALMA Survey of CO isotopologue emission from Protoplanetary Disks in Chamaeleon I
• Multiple rings in the transition disk and companion candidates around RXJ1615.3-3255. High contrast imaging with VLT/SPHERE
• Measurement of Circumstellar Disk Sizes in the Upper Scorpius OB Association with ALMA
• A cavity and further radial substructures in the disk around HD~97048
• A survey of C2H, HCN, and C18O in protoplanetary disks
• A case of simultaneous star and planet formation
• Annular substructures in the transition disks around LkCa 15 and J1610
• Vortices and spirals in the HD135344B transition disk
• The Sizes and Depletions of the Dust and Gas Cavities in the Transitional Disk J160421.7-213028
• An ALMA Survey of H${}_2$CO in Protoplanetary Disks
• Variable dynamics in the inner disk of HD 135344B revealed with multi-epoch scattered light imaging
• A Tale of Planet Formation: From Dust to Planets
• The Disc Miner I: A statistical framework to detect and quantify kinematical perturbations driven by young planets in discs
• A population of transition disks around evolved stars: Fingerprints of planets? Catalog of disks surrounding Galactic post-AGB binaries
• A dusty filament and turbulent CO spirals in HD135344B-SAO206462
• Mass constraints for 15 protoplanetary disks from HD 1-0
• Chemically tracing the water snowline in protoplanetary disks with HCO${}^{+}$
• Wind-driven Accretion in Transitional Protostellar Disks
• Sulphur monoxide emission tracing an embedded planet in the HD 100546 protoplanetary disk
• Gas temperature structure across transition disk cavities
• Transition disks: the observational revolution from SEDs to imaging
• A 80 au cavity in the disk around HD 34282
• New constraints on the disk characteristics and companion candidates around T Cha with VLT/SPHERE
• exoALMA IV: Substructures, Asymmetries, and the Faint Outer Disk in Continuum Emission
• Accreting Transition Discs with large cavities created by X-ray photoevaporation in C and O depleted discs
• The Frequency Of Binary Star Interlopers Amongst Transitional Discs
• A gas density drop in the inner 6 AU of the transition disk around the Herbig Ae star HD 139614: Further evidence for a giant planet inside the disk?
• Searching for H${}_{\alpha }$-emitting sources in the gaps of five transitional disks. SPHERE/ZIMPOL high-contrast imaging
• ISPY-NACO Imaging Survey for Planets around Young stars. The demographics of forming planets embedded in protoplanetary disks
• Magnetised Winds in Transition Discs I: 2.5D Global Simulations
• An Inner Disk in the Large Gap of the Transition Disk SR 24S
• Dust Traps and the Formation of Cavities in Transition Discs: A millimetre to sub-millimetre comparison survey
• The SPHERE view of three interacting twin disc systems in polarised light
• Dust traps as planetary birthsites: basics and vortex formation
• The dipper population of Taurus seen with K2
• Observational signatures of eccentric Jupiters inside gas cavities in protoplanetary discs
• Exploring HNC and HCN line emission as probes of the protoplanetary disk temperature
• Vertically extended and asymmetric CN emission in the Elias 2-27 protoplanetary disk
• Disentangling protoplanetary disk gas mass and carbon depletion through combined atomic and molecular tracers
• The evolution of circumstellar discs in the Galactic Centre: an application to the G-clouds
• A multi-scale exploration of a massive young stellar object - a transition disk around G305.20+0.21?
• Gap Opening and Inner Disk Structure in the Strongly Accreting Transition Disk of DM Tau
• Clumpy accretion in pre-main-sequence stars as a source of perturbations in circumstellar disks
• HCO+ Detection of Dust-Depleted Gas in the Inner Hole of the LkCa 15 Pre-Transitional Disk
• SUBARU Near-Infrared Imaging Polarimetry of Misaligned Disks Around The SR24 Hierarchical Triple System
• Intermediate mass T Tauri disk masses and a comparison to their Herbig disk descendants
• Long-Term Dynamics of Planetesimals in Planetary Chaotic Zones
• Gas distribution in ODISEA sources from ALMA long-baseline observations in ${}^{12}$CO(2-1)
• Self-Sustained Recycling in the Inner Dust Ring of Pre-Transitional Disks
• Testing planet formation from the ultraviolet to the millimeter
• Catastrophic events in protoplanetary disks and their observational manifestations
• Multi-band reflectance and shadowing of RX J1604.3-2130 protoplanetary disk in scattered light
• Molecules with ALMA at Planet-forming Scales (MAPS) III: Characteristics of Radial Chemical Substructures
• On the cavity size in circumbinary discs
• Protoplanetary Disk Chemistry