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Record W1972307908 · doi:10.1088/0004-6256/145/1/12

THE ACCELERATING JET OF 3C 279

2012· article· en· W1972307908 on OpenAlexfundno aff
S. D. Bloom, Christian M. Fromm, E. Ros

Bibliographic record

VenueThe Astronomical Journal · 2012
Typearticle
Languageen
FieldPhysics and Astronomy
TopicAstrophysics and Cosmic Phenomena
Canadian institutionsnot available
FundersNatural Sciences and Engineering Research Council of Canada
KeywordsPhysicsLorentz factorSuperluminal motionJet (fluid)Viewing angleFlux (metallurgy)AstrophysicsQuasarAzimuthRange (aeronautics)Lorentz transformationComputational physicsMechanicsClassical mechanicsOpticsGalaxy

Abstract

fetched live from OpenAlex

Analysis of the proper motions of the sub-parsec scale jet of the quasar 3C 279 at 15 GHz with the VLBA shows significant accelerations in four of nine superluminal features. Analysis of these motions is combined with the analysis of flux density light curves to constrain values of Lorentz factor and viewing angle (and their derivatives) for each component. The data for each of these components is consistent with significant changes to the Lorentz factor, viewing angle and azimuthal angle, suggesting jet bending with changes in speed. We see that for these observed components Lorentz factors are in the range Γ = 10−41, viewing angles are in the range ϑ = 0.1◦ −5.0◦ , and intrinsic (source frame) flux density is in the range, Fν , int = 1.5×10−9−1.5×10−5 Jy. Considering individual components, the Lorentz factors vary from Γ = 11 − 16 for C1, Γ = 31 − 41 for C5, Γ = 29 − 41 for C6 and Γ = 9 − 12 for C8, indicating that there is no single underlying flow speed to the jet and likely we are seeing pattern speeds from shocks in the jet. The viewing angles vary in time from 0.6◦ to 1.5◦ in the case of C1 (the least extreme example), vary from 0.5◦ to 5.0◦ in the case of C8 and vary from 0.1◦ to 0.9◦ for C5 (the last two being the most extreme examples). The intrinsic flux density varies by factors from 1.4 for C8 and 430 for C5. Theoretical analysis of the accelerations also indicates potential jet bending. In addition, for one component, C5, polarization measurements also set limits to the trajectory of the jet.

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 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: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.289
Threshold uncertainty score0.363

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)0.0000.000

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 head0.016
GPT teacher head0.235
Teacher spread0.219 · 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 teacher head, 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

Citations14
Published2012
Admission routes1
Has abstractyes

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