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Record W1988119723 · doi:10.1088/0004-637x/696/2/1755

SPECTROSCOPIC ANALYSIS OF DA WHITE DWARFS: STARK BROADENING OF HYDROGEN LINES INCLUDING NONIDEAL EFFECTS

2009· article· en· W1988119723 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

VenueThe Astrophysical Journal · 2009
Typearticle
Languageen
FieldPhysics and Astronomy
TopicAstro and Planetary Science
Canadian institutionsUniversité de MontréalCentre for Research in Astrophysics of Québec
Fundersnot available
KeywordsStark effectWhite dwarfPhysicsSpectral lineLine (geometry)Atomic physicsIdeal (ethics)Computational physicsElectronStarsQuantum mechanicsAstrophysicsLaw

Abstract

fetched live from OpenAlex

We present improved calculations for the Stark broadening of hydrogen lines in dense plasmas typical of white dwarf atmospheres. Our new model is based on the unified theory of Stark broadening from Vidal, Cooper, & Smith. For the first time, we account for the non-ideal effects in a consistent way directly inside the line profile calculations. The Hummer & Mihalas theory is used to describe the non-ideal effects due to perturbations on the absorber from protons and electrons. We use a truncation of the electric microfield distribution in the quasi-static proton broadening to take into account the fact that high electric microfields dissociate the upper state of a transition. This approach represents a significant improvement over previous calculations that relied on the use of an ad hoc parameter to mimic these non-ideal effects. We obtain the first model spectra with line profiles that are consistent with the equation of state. We revisit the properties of DA stars in the range 40,000 K > Teff > 13,000 K by analyzing the optical spectra with our improved models. The updated atmospheric parameters are shown to differ substantially from those published in previous studies, with a mean mass shifted by +0.034 Msun. We also show that these revised atmospheric parameters yield absolute visual magnitudes that remain in excellent agreement with trigonometric parallax measurements.

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: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.732
Threshold uncertainty score0.443

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.001
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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 head0.010
GPT teacher head0.253
Teacher spread0.243 · 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