MétaCan
Menu
Back to cohort
Record W1993241454 · doi:10.1086/504066

AmFm Stars as a Test of Rotational Mixing Models

2006· article· en· W1993241454 on OpenAlexaff
S. Talon, O. Richard, G. Michaud

Bibliographic record

VenueThe Astrophysical Journal · 2006
Typearticle
Languageen
FieldPhysics and Astronomy
TopicStellar, planetary, and galactic studies
Canadian institutionsUniversité de Montréal
Fundersnot available
KeywordsPhysicsStarsAstrophysicsSupergiantTurbulenceStellar evolutionRadiative transferAngular momentumDiffusionAbundance (ecology)AnisotropyClassical mechanicsMechanicsThermodynamics

Abstract

fetched live from OpenAlex

Stellar evolution models have been calculated for stars of 1.7-2.5 M ☉ with both the Geneva-Toulouse and Montreal codes. In the Geneva-Toulouse code, the internal evolution of angular momentum is calculated self-consistently along with the transport of a few species. In the Montreal code, the transport of 24 species is treated in detail, taking into account radiative accelerations, thermal diffusion, and gravitational settling, along with the turbulent diffusion coefficients calculated in the Geneva-Toulouse code. It is verified that the two codes lead to very similar internal structure for a given mass. The calculated surface abundances are compared to abundance anomalies observed on AmFm stars. It is found that with approximately the same parameters as used for other types of stars, the Geneva-Toulouse code leads to turbulent transport coefficients that produce abundance anomalies consistent with the observed ones for HD 73045, HD 23610, and Sirius. Taking into account the effect of the anisotropy of turbulence on vertical transport plays an important role, although the level of anisotropy in stellar envelopes is very uncertain; this effect is usually neglected in calculations. The stabilizing effect of the mean molecular weight gradient can also be important. The current level of accuracy of observed abundances only permits to choose within a one-parameter family of models. To distinguish between turbulent models with different interior profiles, an accuracy of 0.03 dex is required of abundance determinations, a level of accuracy that is not currently achieved. It is also shown that taking into account the pre-main-sequence evolution of the rotation profile leads to an important reduction in the Ω dependence of turbulent transport for slow rotators.

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 imitation

Not 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.

metaresearch head score (Codex)0.004
metaresearch head score (Gemma)0.005
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.004
Threshold uncertainty score0.019

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0040.005
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0010.001
Science and technology studies0.0010.001
Scholarly communication0.0020.001
Open science0.0010.001
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0030.001

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.

Opus teacher head0.011
GPT teacher head0.219
Teacher spread0.208 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designSimulation or modeling
Domainnot available
GenreEmpirical

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".

Quick stats

Citations67
Published2006
Admission routes1
Has abstractyes

Explore more

Same venueThe Astrophysical JournalSame topicStellar, planetary, and galactic studiesFrench-language works237,207