MétaCan
Menu
Back to cohort

Evidence for an accretion stream in 4U 1907+09

2010· article· en· W2159885621 on OpenAlexaff
M. Kostka, D. A. Leahy

Bibliographic record

VenueMonthly Notices of the Royal Astronomical Society · 2010
Typearticle
Languageen
FieldPhysics and Astronomy
TopicAstrophysical Phenomena and Observations
Canadian institutionsUniversity of Calgary
Fundersnot available
KeywordsPhysicsAstrophysicsAccretion (finance)Neutron starFlux (metallurgy)X-ray binaryLuminosityOrbital eccentricityAstronomyStarsGalaxy

Abstract

fetched live from OpenAlex

The X-ray binary system 4U 1907+09 contains an accretion-powered X-ray pulsar in an eccentric orbit around a massive early-type companion star. It has been previously suggested that a trailing gas stream along with strong stellar winds could describe the orbital variations in X-ray flux. In this work, 12 yr of X-ray observations from the Rossi X-ray Timing Explorer/All-Sky Monitor are analysed. We study both the X-ray flux and column density dependence on the orbital phase. The dynamics of the wind and stream are calculated for various companion star radii, system inclinations and eccentricities; the wind and stream model is parametrized by companion star rotation, stellar wind velocity, stream width and density. These parameters are taken as inputs to compute the expected accretion luminosity which is then compared to the observed flux versus the orbital phase. The column density along the line of sight to the neutron star is calculated using the best-fitting results from the flux analysis and verifies the high extinction in the direction of 4U 1907+09. We find that the stream component of accretion contributes significantly to describing the orbital variations in X-ray flux observed in 4U 1907+09. The best-fitting free parameters of our wind and stream model such as mass-loss rate, terminal wind velocity, companion star rotation speed and interstellar extinction are found to be consistent with literature values for 4U 1907+09. The best fit to the data was found at higher values of eccentricity (e= 0.31) and lower companion star radii (Rc= 16–21 R⊙).

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)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.005
Threshold uncertainty score0.010

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0010.000
Scholarly communication0.0010.000
Open science0.0000.001
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 head0.026
GPT teacher head0.260
Teacher spread0.235 · 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 designObservational
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

Citations7
Published2010
Admission routes1
Has abstractyes

Explore more

Same venueMonthly Notices of the Royal Astronomical SocietySame topicAstrophysical Phenomena and ObservationsFrench-language works237,207