Revealing dust segregation in protoplanetary discs with the help of multi-frequency spectral index maps

Abstract

Dust is known to drift and grow in protoplanetary discs, which results in dust segregation over the disc extent. Maps of the spectral index $\alpha$ are a common tool for studying the dust content in protoplanetary discs. The analysis of observationally derived maps reveals significant gradients of the spectral index, confirming that dust evolves in the disc, but a more detailed information about the dust redistribution is required to make inferences about the early stages of dust growth. We calculated the spectral index maps based on the results of numerical hydrodynamical simulations using the FEOSAD code, which allows studying a long-term dynamics of a self-gravitating viscous disc populated with coagulating, drifting, and fragmenting dust. Here we demonstrate that values of the spectral index estimated for different wavelength intervals within the far-infrared and radio bands reveal the presence of dust grains of various sizes. Specifically, we show that the disc regions with the maximal spectral index in a specific wavelength interval are the regions with the prevalence of dust grains of a specific size. Thus, a set of spectral index maps derived using different wavelength intervals can be used to recover the dust size-distribution over the disc extent.

arXiv commentAccepted for publication in MNRAS 2019

References in corpus (21)

• Dust and Gas in the disc of HL Tauri: Surface density, dust settling, and dust-to-gas ratio
• Rapid Coagulation of Porous Dust Aggregates Outside the Snow Line: A Pathway to Successful Icy Planetesimal Formation
• Dust Properties of Protoplanetary Disks in the Taurus-Auriga Star Forming Region from Millimeter Wavelengths
• The Disk Substructures at High Angular Resolution Project (DSHARP): V. Interpreting ALMA maps of protoplanetary disks in terms of a dust model
• Constraints on the Radial Variation of Grain Growth in the AS 209 Circumstellar Disk
• Large dust particles in disks around T Tauri stars
• Dust grain growth in rho-Ophiuchi protoplanetary disks
• Large grains in the disk of CQ Tau
• Dust Evolution in Protoplanetary Disks
• A multi-wavelength analysis for interferometric (sub-)mm observations of protoplanetary disks: radial constraints on the dust properties and the disk structure
• A search for evolved dust in Herbig Ae stars
• Investigating planet formation in circumstellar disks: CARMA observations of RY Tau and DG Tau
• CO and dust properties in the TW Hya disk from high-resolution ALMA observations
• Opacity of fluffy dust aggregates
• Testing the theory of grain growth and fragmentation by millimeter observations of protoplanetary disks
• Grain Growth in the Circumstellar Disks of the Young Stars CY Tau and DoAr 25
• A Gap with a Deficit of Large Grains in the protoplanetary disk around TW Hya
• The early evolution of viscous and self-gravitating circumstellar disks with a dust component
• Observations of Solids in Protoplanetary Disks
• Grain growth signatures in the protoplanetary discs of Chamaeleon and Lupus
• New constraints on dust grain size and distribution in CQ Tau

Cited by in corpus (12)

• Observations of edge-on protoplanetary disks with ALMA I. Results from continuum data
• Massive compact disks around FU Orionis-type young eruptive stars revealed by ALMA
• Millimeter-sized Dust Grains Appear Surviving the Water-sublimating Temperature in the Inner 10 au of the FU Ori Disk
• Evolution of dust in protoplanetary disks of eruptive stars
• Gravitoviscous protoplanetary disks with a dust component. III. Evolution of gas, dust, and pebbles
• Gravitoviscous protoplanetary disks with a dust component. V. The dynamic model for freeze-out and sublimation of volatiles
• Observing planet-driven dust spirals with ALMA
• The origin of tail-like structures around protoplanetary disks
• Gravitoviscous Protoplanetary Discs with a Dust Component. IV. Disc Outer Edges, Spectral Indices, and Opacity Gaps
• Coagulation-Fragmentation Equilibrium for Charged Dust: Abundance of Submicron Grains Increases Dramatically in Protoplanetary Disks
• Testing velocity kinks as a planet-detection method: Do velocity kinks in surface gas emission trace planetary spiral wakes in the midplane continuum?
• C/O ratios in self-gravitating protoplanetary discs with dust evolution