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Record W2145205259

Magnetic models of slowly rotating magnetic Ap stars: aligned magnetic and rotation axes

2000· article· en· W2145205259 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueA&A · 2000
Typearticle
Languageen
FieldEngineering
TopicSpace Technology and Applications
Canadian institutionsWestern University
Fundersnot available
KeywordsStarsPhysicsAstrophysicsQuadrupoleMagnetic fieldField (mathematics)Rotation periodDipoleRotation (mathematics)Multipole expansionMagnetic dipoleGeometryMathematicsQuantum mechanics
DOInot available

Abstract

fetched live from OpenAlex

As a result of major surveys carried out during the past decade by Mathys and collaborators, we now have mea- surements with full phase coverage of several magnetic field moments, including the mean longitudinal field B', the mean field modulus Bs, and in most cases the mean quadratic field Bmq and mean crossover field Bxover, for a sample of 24 chem- ically peculiar magnetic (Ap) stars. This represents an increase of a factor of order five in the stellar sample with data of this quality, compared to the situation a decade ago. We exploit this dataset to derive general and statistical prop- erties of the stars in the sample, as follows. First, we fit the avail- able field moment observations assuming a simple, axisymmet- ric multipole magnetic field expansion (with dipole, quadrupole, and octupole components) over each stellar surface. We show that this representation, though not exact, gives an adequate description of the available data for all the stars in this sam- ple, although the fit parameters are in many cases not unique. We find that many of the stars require an important quadrupole and/or octupole field component to satisfy the observations, and that some (usually small) deviations from our assumed axisym- metric field distributions are certainly present. We examine the inclination i (0 i 90) of the rotation axis to the line of sight and the obliquity (0 90) of the magnetic field with respect to the rotation axis, and show that the stars with periods of the order of a month or longer have systematically small values of : slowly rotating magnetic stars generally have their magnetic and rotation axes aligned to within about 20 , unlike the short period magnetic Ap stars, in which is usually large. This is a qualitatively new result, and one which is very important for efforts to understand the evolution of magnetic fields and angular momentum in the magnetic Ap stars.

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.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation 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 score0.893
Threshold uncertainty score0.561

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

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.

Opus teacher head0.007
GPT teacher head0.200
Teacher spread0.193 · 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