Characterization of the dust content in the ring around Sz 91: indications for planetesimal formation?

Abstract

One of the most important questions in the field of planet formation is how mm-cm sized dust particles overcome the radial drift and fragmentation barriers to form kilometer-sized planetesimals. ALMA observations of protoplanetary disks, in particular transition disks or disks with clear signs of substructures, can provide new constraints on theories of grain growth and planetesimal formation and therefore represent one possibility to progress on this issue. We here present ALMA band 4 (2.1 mm) observations of the transition disk system Sz 91 and combine them with previously obtained band 6 (1.3 mm) and 7 (0.9 mm) observations. Sz 91 with its well defined mm-ring, more extended gas disk, and evidence of smaller dust particles close to the star, is a clear case of dust filtering and the accumulation of mm sized particles in a gas pressure bump. We computed the spectral index (nearly constant at $\sim$3.34), optical depth (marginally optically thick), and maximum grain size ($\sim 0.61$ mm) in the dust ring from the multi-wavelength ALMA observations and compared the results with recently published simulations of grain growth in disk substructures. Our observational results are in very good agreement with the predictions of models for grain growth in dust rings that include fragmentation and planetesimal formation through the streaming instability.

arXiv commentAccepted for publication in the ApJ 19 pages, 13 figures

References in corpus (81)

• Astropy: A Community Python Package for Astronomy
• The NumPy array: a structure for efficient numerical computation
• The Gaia mission
• Protoplanetary Disks and Their Evolution
• First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
• The Disk Substructures at High Angular Resolution Project (DSHARP): I. Motivation, Sample, Calibration, and Overview
• Circumstellar Dust Disks in Taurus-Auriga: The Submillimeter Perspective
• Resolved Images of Large Cavities in Protoplanetary Transition Disks
• ALMA Survey of Lupus Protoplanetary Disks I: Dust and Gas Masses
• Evidence for a developing gap in a 10 Myr old protoplanetary disk
• The Disk Substructures at High Angular Resolution Project (DSHARP): II. Characteristics of Annular Substructures
• X-Shooter spectroscopy of young stellar objects in Lupus: Accretion properties of class II and transitional objects
• Accretion in Brown Dwarfs: an Infrared View
• Observations of gas flows inside a protoplanetary gap
• The Disk Substructures at High Angular Resolution Project (DSHARP) VI: Dust trapping in thin-ringed protoplanetary disks
• Gaps, Rings, and Non-Axisymmetric Structures in Protoplanetary Disks - From Simulations to ALMA Observations
• The Disk Substructures at High Angular Resolution Project (DSHARP): V. Interpreting ALMA maps of protoplanetary disks in terms of a dust model
• ALMA Survey of Lupus Protoplanetary Disks II: Gas Disk Radii
• Dust filtration at gap edges: Implications for the spectral energy distributions of discs with embedded planets
• PROSAC: A Submillimeter Array Survey of Low-Mass Protostars. I. Overview of Program: Envelopes, Disks, Outflows and Hot Cores
• Compact Disks in a High Resolution ALMA Survey of Dust Structures in the Taurus Molecular Cloud
• Shadows cast by a warp in the HD 142527 protoplanetary disk
• Constraints on the Radial Variation of Grain Growth in the AS 209 Circumstellar Disk
• Dust dynamics during protoplanetary disc clearing
• Resolved gas cavities in transitional disks inferred from CO isotopologues with ALMA
• Challenges in Forming Planets by Gravitational Instability: Disk Irradiation and Clump Migration, Accretion & Tidal Destructio
• Large grains in the disk of CQ Tau
• One Solution to the Mass Budget Problem for Planet Formation: Optically Thick Disks with Dust Scattering
• Multiple Disk Gaps and Rings Generated by a Single Super-Earth
• Dust depleted inner disks in a large sample of transition disks through long-baseline ALMA observations
• Small vs large dust grains in transitional disks: do different cavity sizes indicate a planet?
• The Disk Substructures at High Angular Resolution Project (DSHARP): III. Spiral Structures in the Millimeter Continuum of the Elias 27, IM Lup, and WaOph 6 Disks
• The Radial Distribution of Dust Particles in the HL Tau Disk from ALMA and VLA Observations
• The anomalously low (sub)millimeter spectral indices of some protoplanetary disks may be explained by dust self-scattering
• Detection of exocometary CO within the 440 Myr-old Fomalhaut belt: a similar CO+CO${}_2$ ice abundance in exocomets and Solar System comets
• Testing the theory of grain growth and fragmentation by millimeter observations of protoplanetary disks
• The Ophiuchus DIsc Survey Employing ALMA (ODISEA)-III: the evolution of substructures in massive discs at 3-5 au resolution
• New insights into the nature of transition disks from a complete disk survey of the Lupus star forming region
• Molecules with ALMA at Planet-forming Scales (MAPS) XIV: Revealing disk substructures in multi-wavelength continuum emission
• Grain Growth in the Circumstellar Disks of the Young Stars CY Tau and DoAr 25
• Characterizing the dust content of disk substructures in TW Hya
• On the diversity of asymmetries in gapped protoplanetary disks
• Sulfur chemistry in protoplanetary disks: CS and H2CS
• Spiral arms in the disk of HD 142527 from CO emission lines with ALMA
• Homogeneous Analysis of the Dust Morphology of Transition Disks Observed with ALMA: Investigating dust trapping and the origin of the cavities
• Measurement of Circumstellar Disk Sizes in the Upper Scorpius OB Association with ALMA
• Temperature, Mass and Turbulence: A Spatially Resolved Multi-Band Non-LTE Analysis of CS in TW~Hya
• 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
• A Gap with a Deficit of Large Grains in the protoplanetary disk around TW Hya
• Including Dust Coagulation in Hydrodynamic Models of Protoplanetary Disks: Dust Evolution in the Vicinity of a Jupiter-mass Planet
• Protoplanetary Disk Rings as Sites for Planetesimal Formation
• The DSHARP Rings: Evidence of Ongoing Planetesimal Formation?
• Two populations of transition discs?
• Chemistry in Disks X: The Molecular Content of Proto-planetary Disks in Taurus
• The Nature of Transition Circumstellar Disks II. Southern Molecular Clouds
• Testing particle trapping in transition disks with ALMA
• Grain growth signatures in the protoplanetary discs of Chamaeleon and Lupus
• A tunnel and a traffic jam: How transition disks maintain a detectable warm dust component despite the presence of a large planet-carved gap
• A concentration of centimeter-sized grains in the Oph IRS 48 dust trap
• Millimetre spectral indices of transition disks and their relation to the cavity radius
• The Flying Saucer: Tomography of the thermal and density gas structure of an edge-on protoplanetary disk
• First detection of H${}_2$S in a protoplanetary disk. The dense GG Tau A ring
• Giant planet formation at the pressure maxima of protoplanetary disks II. A hybrid accretion scenario
• New Constraints From Dust Lines On The Surface Densities Of Protoplanetary Disks
• Dust and gas density evolution at a radial pressure bump in protoplanetary disks
• Multiple rings in the transitional disk of GM Aurigae revealed by VLA and ALMA
• The first ALMA survey of protoplanetary discs at 3 mm: demographics of grain growth in the Lupus region
• Effects of scattering, temperature gradients, and settling on the derived dust properties of observed protoplanetary disks
• Variability and dust filtration in the transition disk J160421.7-213028 observed in optical scattered light
• A ring-like concentration of mm-sized particles in Sz 91
• On the Effects of Self-Obscuration in the (Sub-)Millimeter Spectral Indices and Appearance of Protostellar Disks
• An analytical model of radial dust trapping in protoplanetary disks
• Gas inside the 97 au cavity around the transition disk Sz\,91
• A bright inner disk and structures in the transition disk around the very low-mass star CIDA 1
• An Inner Disk in the Large Gap of the Transition Disk SR 24S
• The Flared Gas Structure of the Transitional Disk around Sz 91
• Dust Traps and the Formation of Cavities in Transition Discs: A millimetre to sub-millimetre comparison survey
• Radio Monitoring of Protoplanetary Discs
• Detailed modeling of dust distribution in the disk of HD 142527
• Constraining the properties of transitional disks in Chamaeleon I with Herschel
• NaCo polarimetric observations of Sz 91 transitional disk: a remarkable case of dust filtering