X-ray photoevaporation's limited success in the formation of planetesimals by the streaming instability

Abstract

The streaming instability is often invoked as solution to the fragmentation and drift barriers in planetesimal formation, catalyzing the aggregation of dust on kyr timescales to grow km-sized cores. However there remains a lack of consensus on the physical mechanism(s) responsible for initiating it. One potential avenue is disc photoevaporation, wherein the preferential removal of relatively dust-free gas increases the disc metallicity. Late in the disc lifetime, photoevaporation dominates viscous accretion, creating a gradient in the depleted gas surface density near the location of the gap. This induces a local pressure maximum that collects drifting dust particles, which may then become susceptible to the streaming instability. Using a one-dimensional viscous evolution model of a disc subject to internal X-ray photoevaporation, we explore the efficacy of this process to build planetestimals. Over a range of parameters we find that the amount of dust mass converted into planetesimals is often < 1 M_Earth and at most a few M_Earth spread across tens of AU. We conclude that photoevaporation may at best be relevant for the formation of debris discs, rather than a common mechanism for the formation of planetary cores. Our results are in contrast to a recent, similar investigation that considered an FUV-driven photoevaporation model and reported the formation of tens of M_Earth at large (> 100 AU) disc radii. The discrepancies are primarily a consequence of the different photoevaporation profiles assumed. Until observations more tightly constrain photoevaporation models, the relevance of this process to the formation of planets remains uncertain.

10 pages, 5 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society

References in corpus (15)

• Coagulation, fragmentation and radial motion of solid particles in protoplanetary disks
• Gas- and dust evolution in protoplanetary disks
• Ring shaped dust accumulation in transition disks
• Dust filtration at gap edges: Implications for the spectral energy distributions of discs with embedded planets
• The stickiness of micrometer-sized water-ice particles
• How to form planetesimals from mm-sized chondrules and chondrule aggregates
• Grain Retention and Formation of Planetesimals near the Snow Line in MRI-driven Turbulent Protoplanetary Disks
• Dust dynamics during protoplanetary disc clearing
• Dust retention in protoplanetary disks
• The Impact of Dust Evolution and Photoevaporation on Disk Dispersal
• Can dust coagulation trigger streaming instability?
• Planetesimal formation via fragmentation in self-gravitating protoplanetary discs
• Spitzer-IRS spectra of disks around T Tauri stars II. PAH emission features
• The link between disc dispersal by photoevaporation and the semi-major axis distribution of exoplanets
• Planetesimal formation in self-gravitating discs: the effects of particle self-gravity and back-reaction

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• Bifurcation of planetary building blocks during Solar System formation
• How efficient is the streaming instability in viscous protoplanetary disks?
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• Giant planet formation at the pressure maxima of protoplanetary disks II. A hybrid accretion scenario
• On the coexistence of the streaming instability and the vertical shear instability in protoplanetary disks
• Fingerprints of giant planets in the composition of solar twins
• Most super-Earths formed by dry pebble accretion are less massive than 5 Earth masses
• A dusty origin for the correlation between protoplanetary disc accretion rates and dust masses
• Modeling the delivery of dust from discs to ionized winds
• Constraining planetesimal stirring: how sharp are debris disc edges?
• The imprint of X-ray photoevaporation of planet-forming discs on the orbital distribution of giant planets
• The formation of wide exoKuiper belts from migrating dust traps
• Primordial Dusty Rings and Episodic Outbursts in Protoplanetary Discs
• Circularizing Planet Nine through dynamical friction with an extended, cold planetesimal belt
• Dust entrainment in photoevaporative winds: Densities and imaging
• Millimeter emission in photoevaporating disks is determined by early substructures
• Formation of Multiple Dynamical Classes in the Kuiper Belt via Disk Dissipation
• Effects of Stellar X-ray Photoevaporation on Planetesimal Formation via the Streaming Instability
• Formation of ring-like structures in flared α-discs with X-ray/FUV photoevaporation