Gravitational instability in binary protoplanetary discs: new constraints on giant planet formation
Bibliographic record
Abstract
We use high-resolution three-dimensional smoothed particle hydrodynamic (SPH) simulations to study the evolution of self-gravitating binary protoplanetary discs. Heating by shocks and cooling is included. We consider different orbital separations and masses of the discs. Massive discs (M∼ 0.1 M⊙) that fragment in isolation as a result of gravitational instability develop only transient overdensities in binary systems with a separation of about 60 au. This is true even when the cooling time is significantly shorter than the orbital time because efficient heating owing to strong tidally induced spiral shocks dominates. The resulting temperatures, above 200 K, would vaporize water ice in the outer disc, posing a problem even for the other model of giant planet formation, core accretion. Light discs (M∼ 0.01 M⊙) do not fragment but remain cold because their low self-gravity inhibits strong shocks. Core accretion would not be hampered in them. At separations of about 120 au, tidally induced spiral shocks weaken significantly and fragmentation occurs similarly to isolated systems. If disc instability is the main formation mechanism for giant planets, ongoing surveys targeting binary systems should find considerably fewer planets in systems with separations below 100 au.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".