JWST/MIRI survey of 2-6 Myr Upper Scorpius disks finds diverse chemotypes, 10-1000x lower water luminosities, and evidence that outer dust traps control inner-disk chemistry.
hub Mixed citations
Observations of Protoplanetary Disk Structures
Mixed citation behavior. Most common role is background (50%).
19
Pith papers citing it
395
external citations · Pith
Background
50% of classified citations
abstract
The disks that orbit young stars are the essential conduits and reservoirs of material for star and planet formation. Their structures, meaning the spatial variations of the disk physical conditions, reflect the underlying mechanisms that drive those formation processes. Observations of the solids and gas in these disks, particularly at high resolution, provide fundamental insights on their mass distributions, dynamical states, and evolutionary behaviors. Over the past decade, rapid developments in these areas have largely been driven by observations with the Atacama Large Millimeter/submillimeter Array (ALMA). This review highlights the state of observational research on disk structures, emphasizing three key conclusions that reflect the main branches of the field: (1) Relationships among disk structure properties are also linked to the masses, environments, and evolutionary states of their stellar hosts; (2) There is clear, qualitative evidence for the growth and migration of disk solids, although the implied evolutionary timescales suggest the classical assumption of a smooth gas disk is inappropriate; and (3) Small-scale substructures with a variety of morphologies, locations, scales, and amplitudes -- presumably tracing local gas pressure maxima -- broadly influence the physical and observational properties of disks. The last point especially is reshaping the field, with the recognition that these disk substructures likely trace active sites of planetesimal growth or are the hallmarks of planetary systems at their formation epoch.
hub tools
citation-role summary
background 4
method 2
citation-polarity summary
years
2026 19representative citing papers
Older Upper Scorpius disks show reduced molecular emission and hints of higher inner-gas C/O ratios than young disks, indicating chemical evolution consistent with pebble drift.
Common analytic approximations underestimate protoplanetary disk millimeter continuum emission by 10-15%, causing overestimates of optical depth, mass, and temperature in SED analyses.
Observations of the HK Tau binary with JWST reveal gas-phase molecular lines in the low-inclination primary and ice absorption features in the edge-on secondary, enabled by their differing inclinations.
High-contrast imaging of HD 142527 reveals a candidate companion at ~14 au and an Hα spiral in the inner disk, possibly tracing accretion flows linked to companion B.
Radiative transfer modeling of protostellar ices shows absorption originates mainly from 1000-2000 au at the cavity-envelope transition, with apparent CO2/H2O and CO/H2O ratios potentially underestimated due to line-of-sight effects.
Updated DALI models reproduce observed C2H2 fluxes with solar C/O and find the C2H2/H2O flux ratio sensitive to elemental abundances and small-grain abundance in planet-forming disk regions.
Nonlinear shock formation dominates angular momentum deposition from planet-induced density waves, cooling matches it for sub-thermal planets, and viscosity only matters at unrealistically high values.
ALMA observations of 100 Ophiuchus discs show substructures linked to giant planet formation are common in discs above 10 Earth masses of dust and increase from Class I to Class II stages.
Synthetic SKA-Mid observations of simulated MHD and photoevaporative disk winds show that free-free emission is detectable in hours and stacked hydrogen recombination lines are spectrally resolvable in ~10 hours.
Numerical simulations of porous fractal and consolidated particles show stronger forward scattering, broader polarization peaks, and lower absorption per unit mass than compact spheres, implying larger dust masses from observed fluxes.
Stronger radiation environments produce more massive, hotter protostellar discs whose fragments are large and disruptive rather than planetary-mass.
Two migrating super-Earths in low-viscosity disks trigger narrow and broad dust substructures with high dust-to-gas ratios favorable for planetesimal formation.
An upgraded planet population synthesis model incorporates post-disc dynamical evolution and atmospheric enrichment to generate synthetic exoplanet populations with improved fidelity to N-body results and observations.
A millimeter survey detects disks around five Herbig Be stars and shows no evidence of rapid disk dissipation with increasing stellar mass.
SKAO will enable the first large-scale high-resolution surveys of cm-wavelength disk emission to constrain dust growth, pebble demographics, and planet formation processes.
This review chapter discusses open questions on protoplanetary disk substructures and how SKA-Mid continuum observations at 12.5 GHz can help resolve them.
The Bern Model has incorporated MHD disk evolution, pebble accretion, and improved interiors, yielding quantitative matches to exoplanet mass functions, radius distributions, and system architectures.
ALMA observed 3933 independent coordinates in nearby star-forming regions for disks and planet formation, analyzed by sky location, frequency coverage, exposure time, spectral lines, and angular resolution.
citing papers explorer
-
Chemical Divergence and Water Depletion: Gas Properties of Evolved Upper Scorpius Disks Revealed by JWST/MIRI
JWST/MIRI survey of 2-6 Myr Upper Scorpius disks finds diverse chemotypes, 10-1000x lower water luminosities, and evidence that outer dust traps control inner-disk chemistry.
-
From Young to Older Disks: JWST/MIRI Evidence for Fading Molecular Emission and Hints for Elevated C/O in Upper Scorpius
Older Upper Scorpius disks show reduced molecular emission and hints of higher inner-gas C/O ratios than young disks, indicating chemical evolution consistent with pebble drift.
-
Millimeter dust continuum and polarization in protoplanetary disks with scattering: A slab model
Common analytic approximations underestimate protoplanetary disk millimeter continuum emission by 10-15%, causing overestimates of optical depth, mass, and temperature in SED analyses.
-
MINDS: Complementary inclinations in the binary system HK Tau reveal gas- and ice-phase chemistry
Observations of the HK Tau binary with JWST reveal gas-phase molecular lines in the low-inclination primary and ice absorption features in the edge-on secondary, enabled by their differing inclinations.
-
Exploration of the inner region of the system HD 142527
High-contrast imaging of HD 142527 reveals a candidate companion at ~14 au and an Hα spiral in the inner disk, possibly tracing accretion flows linked to companion B.
-
CORINOS V: Radiative transfer effects in protostellar ice observations
Radiative transfer modeling of protostellar ices shows absorption originates mainly from 1000-2000 au at the cavity-envelope transition, with apparent CO2/H2O and CO/H2O ratios potentially underestimated due to line-of-sight effects.
-
Chemistry and IR emission of acetylene in planet-forming regions of T Tauri disks. Impact of elemental abundances and dust properties
Updated DALI models reproduce observed C2H2 fluxes with solar C/O and find the C2H2/H2O flux ratio sensitive to elemental abundances and small-grain abundance in planet-forming disk regions.
-
$\alpha\beta q_\mathrm{th}$-mapping of planet-induced density wave damping in protoplanetary discs
Nonlinear shock formation dominates angular momentum deposition from planet-induced density waves, cooling matches it for sub-thermal planets, and viscosity only matters at unrealistically high values.
-
The Ophiuchus DIsc Survey Employing ALMA (ODISEA). Substructures as a function of SED Class and disc mass in 100 systems
ALMA observations of 100 Ophiuchus discs show substructures linked to giant planet formation are common in discs above 10 Earth masses of dust and increase from Class I to Class II stages.
-
Ionized gas emission in protoplanetary disks with the SKAO
Synthetic SKA-Mid observations of simulated MHD and photoevaporative disk winds show that free-free emission is detectable in hours and stacked hydrogen recombination lines are spectrally resolvable in ~10 hours.
-
Modeling (Sub-)millimeter Scattering Properties of Fractal and Consolidated Porous Particles: Applications to Protoplanetary Disks
Numerical simulations of porous fractal and consolidated particles show stronger forward scattering, broader polarization peaks, and lower absorption per unit mass than compact spheres, implying larger dust masses from observed fluxes.
-
The Impact of Radiation Environment on the Evolution and Fragmentation of Protostellar Discs
Stronger radiation environments produce more massive, hotter protostellar discs whose fragments are large and disruptive rather than planetary-mass.
-
On the Dust Substructures Triggered by Two Super-Earths Migrating in Low-viscosity Disks
Two migrating super-Earths in low-viscosity disks trigger narrow and broad dust substructures with high dust-to-gas ratios favorable for planetesimal formation.
-
Rapid and Predictive Planet Population Synthesis Model (RAPPS) I. Upgraded model and resulting synthetic populations
An upgraded planet population synthesis model incorporates post-disc dynamical evolution and atmospheric enrichment to generate synthetic exoplanet populations with improved fidelity to N-body results and observations.
-
A $\lambda=1.3$ millimeter Survey for Disks around Herbig Be Stars
A millimeter survey detects disks around five Herbig Be stars and shows no evidence of rapid disk dissipation with increasing stellar mass.
-
Demographics of planet-forming disks with the SKAO
SKAO will enable the first large-scale high-resolution surveys of cm-wavelength disk emission to constrain dust growth, pebble demographics, and planet formation processes.
-
Substructures in Planet-Forming Disks with the SKAO
This review chapter discusses open questions on protoplanetary disk substructures and how SKA-Mid continuum observations at 12.5 GHz can help resolve them.
-
The formation of planetary systems: physics, populations, and architectures
The Bern Model has incorporated MHD disk evolution, pebble accretion, and improved interiors, yielding quantitative matches to exoplanet mass functions, radius distributions, and system architectures.
-
An archival summary: 15 years of ALMA observations on disks and planet formation
ALMA observed 3933 independent coordinates in nearby star-forming regions for disks and planet formation, analyzed by sky location, frequency coverage, exposure time, spectral lines, and angular resolution.