Dust mineralogy and variability of the inner PDS 70 disk

Abstract

The inner disk of the young star PDS 70 may be a site of rocky planet formation, with two giant planets detected further out. Solids in the inner disk may inform us about the origin of this inner disk water and nature of the dust in the rocky planet-forming regions. We aim to constrain the chemical composition, lattice structure, and grain sizes of small silicate grains in the inner disk of PDS 70, observed both in JWST/MIRI MRS and Spitzer IRS. We use a dust fitting model, called DuCK, based on a two-layer disk model. We use Gaussian Random Field and Distribution of Hollow Spheres models to obtain two sets of dust opacities. The third set of opacities is obtained from aerosol spectroscopy. We use stoichiometric amorphous silicates, forsterite, and enstatite in our analysis. We also used iron-rich and magnesium-rich amorphous silicate and fayalite dust species to study the iron content. The Gaussian Random Field opacity agrees well with the observed spectrum. In both MIRI and Spitzer spectra, amorphous silicates are the dominant dust species. Crystalline silicates are dominated by iron-poor olivine. We do not find strong evidence for enstatite. Moreover, the MIRI spectrum indicates larger grain sizes than the Spitzer spectrum, indicating a time-variable small grain reservoir. The inner PDS 70 disk is dominated by a variable reservoir of optically thin warm amorphous silicates. We suggest that the small grains detected in the inner PDS 70 disk are likely transported inward from the outer disk as a result of filtration and fragmentation at the ice line. In addition, the variation between MIRI and Spitzer data can be explained by the grain growth over 15 years and a dynamical inner disk where opacity changes occur resulting from the highly variable hot innermost dust reservoir.

arXiv comment18 pages, 13 figures, Accepted by A&A

References in corpus (62)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Multimodal nested sampling: an efficient and robust alternative to MCMC methods for astronomical data analysis
• Bayes in the sky: Bayesian inference and model selection in cosmology
• Importance Nested Sampling and the MultiNest Algorithm
• Discovery of a planetary-mass companion within the gap of the transition disk around PDS 70
• Photodissociation and photoionisation of atoms and molecules of astrophysical interest
• The absence of crystalline silicates in the diffuse interstellar medium
• Two accreting protoplanets around the young star PDS 70
• The Mid-Infrared Instrument for the James Webb Space Telescope I: Introduction
• The Science Performance of JWST as Characterized in Commissioning
• A Survey and Analysis of Spitzer Infrared Spectrograph Spectra of T Tauri Stars in Taurus
• Modeling optical properties of cosmic dust grains using a distribution of hollow spheres
• A 10 micron spectroscopic survey of Herbig Ae star disks: grain growth and crystallization
• CASSIS: The Cornell Atlas of Spitzer/IRS Sources
• Dust Evolution and the Formation of Planetesimals
• C2D Spitzer-IRS spectra of disks around T Tauri stars: I. Silicate emission and grain growth
• Equilibrium chemistry down to 100 K - Impact of silicates and phyllosilicates on carbon/oxygen ratio
• Pixie Dust: The Silicate Features in the Diffuse Interstellar Medium
• Orbital and atmospheric characterization of the planet within the gap of the PDS 70 transition disk
• Dust size distributions in coagulation/fragmentation equilibrium: Numerical solutions and analytical fits
• Planetesimal formation near the snowline: in or out?
• A Circumplanetary Disk Around PDS70c
• The Mid-Infrared Instrument for JWST, II: Design and Build
• JWST MIRI flight performance: The Medium-Resolution Spectrometer
• The Onset of Planet Formation in Brown Dwarf Disks
• VIP: Vortex Image Processing package for high-contrast direct imaging
• The shape and composition of interstellar silicate grains
• The formation and evolution of planetary systems: Grain growth and chemical processing of dust in T Tauri systems
• Submillimeter emission associated with candidate protoplanets
• A Spitzer IRS Study of Infrared Variability in Transitional and Pre-Transitional Disks around T Tauri Stars
• Dust evolution in protoplanetary disks around Herbig Ae/Be stars - The Spitzer view
• Magellan Adaptive Optics Imaging of PDS 70: Measuring the Mass Accretion Rate of a Young Giant Planet within a Gapped Disk
• Polarimetric Imaging of Large Cavity Structures in the Pre-transitional Protoplanetary Disk around PDS 70: Observations of the disk
• Crystalline silicates and dust processing in the protoplanetary disks of the Taurus young cluster
• The Inner Rim Structures of Protoplanetary Discs
• Mid-Infrared Spectroscopy of Disks around Classical T Tauri Stars
• Dust Processing and Grain Growth in Protoplanetary Disks in the Taurus-Auriga Star-Forming Region
• C2D Spitzer-IRS spectra of disks around T Tauri stars. IV. Crystalline silicates
• Water in the terrestrial planet-forming zone of the PDS 70 disk
• 8--13 um spectroscopy of YSOs: Evolution of the silicate feature
• Transient dust in warm debris disks - Detection of Fe-rich olivine grains
• The Structure of Pre-transitional Protoplanetary Disks. II. Azimuthal Asymmetries, Different Radial Distributions of Large and Small Dust Grains in PDS~70
• VLT/SPHERE exploration of the young multiplanetary system PDS70
• Accretion Properties of PDS 70b with MUSE
• A tunnel and a traffic jam: How transition disks maintain a detectable warm dust component despite the presence of a large planet-carved gap
• Hubble Space Telescope UV and H$\alpha$ Measurements of the Accretion Excess Emission from the Young Giant Planet PDS 70 b
• The Long-Lived Disks in the Eta Chamaeleontis Cluster
• Magnetospheric Accretion as a Source of H$\alpha$ Emission from Proto-planets around PDS 70
• On the Evolution of Dust Mineralogy, From Protoplanetary Disks to Planetary Systems
• Comet-like mineralogy of olivine crystals in an extrasolar proto-Kuiper belt
• Differences in the gas and dust distribution in the transitional disk of a sun-like young star, PDS 70
• C2D Spitzer-IRS spectra of disks around T Tauri stars V. Spectral decomposition
• The 10 $\mu$m infrared band of silicate dust: A laboratory study comparing the aerosol and KBr pellet techniques
• The 69 micron forsterite band in spectra of protoplanetary disks - Results from the Herschel DIGIT programme
• Bayesian modelling of clusters of galaxies from multi-frequency pointed Sunyaev--Zel'dovich observations
• Absorption and scattering properties of arbitrarily shaped particles in the Rayleigh domain: A rapid computational method and a theoretical foundation for the statistical approach
• Do we really know the dust? Systematics and uncertainties of the mid-infrared spectral analysis methods
• MINDS: JWST/NIRCam imaging of the protoplanetary disk PDS 70
• Bayesian Analysis of Molecular Emission and Dust Continuum of Protoplanetary Disks
• Constraining the gas distribution in the PDS 70 disk as a method to assess the effect of planet-disk interactions
• Spectral evolution and radial dust transport in the prototype young eruptive system EX Lup
• Spatial distribution of crystalline silicates in protoplanetary disks: How to interpret mid-infrared observations

Cited by in corpus (12)

• Burned to ashes: How the thermal decomposition of refractory organics in the inner protoplanetary disc impacts the gas-phase C/O ratio
• Dust mass in protoplanetary disks with porous dust opacities
• Inner disc and circumplanetary material in the PDS 70 system
• Keplerian motion of a compact source orbiting the inner disc of PDS 70: a third protoplanet in resonance with b and c?
• Accretion Burst Crystallizes Silicates in a Planet-Forming Disk
• MINDS. Cha Hα 1, a brown dwarf with a hydrocarbon-rich disk
• MINDS. Young binary systems with JWST/MIRI: Variable water-rich primaries and extended emission
• Mid-infrared absorption spectra and mass absorption coefficients for 23 chondrites: dependence on composition and grain size
• Interstellar Object 3I/ATLAS Observed from Mars by China's Tianwen-1 Spacecraft
• How leaky? A large parameter study of leaky dust traps to quantify the transport of pebbles and ice in protoplanetary discs
• MINDS: The very low-mass star and brown dwarf sample II. Probing disk settling, dust properties, and dust-gas interplay with JWST/MIRI
• MINDS survey of silicates in T Tauri disks: Correlation between dust and gas