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Pulsar microstructure and its quasi-periodicities with the S2 VLBI system at a resolution of 62.5 nanoseconds

2001· article· en· W3102444828 on OpenAlexaff
M. В. Попов, N. Bartel, W. H. Cannon, A. Yu. Novikov, V. I. Kondratiev, V. I. Altunin

Bibliographic record

VenueCERN Document Server (European Organization for Nuclear Research) · 2001
Typearticle
Languageen
FieldPhysics and Astronomy
TopicRadio Astronomy Observations and Technology
Canadian institutionsYork University
Fundersnot available
KeywordsPulsarAstrophysicsPhysicsMicrostructureAutocorrelationVery-long-baseline interferometryAstronomyOpticsMaterials scienceStatisticsMathematics

Abstract

fetched live from OpenAlex

The microstructure of PSRs B0950+08, B1133+16, and B1929+10 was investigated for a large number of pulses with a time resolution of 62.5 ns, by far the highest for any such statistical study yet. Using the S2 VLBI system, the pulsars were observed in absentia with the 70-m NASA/DSN radio telescope at Tidbinbilla, Australia, at a frequency of 1650 MHz. The data were continuously recorded at the Nyquist sampling rate with 2-bit sampling in the upper and lower sidebands each 16 MHz wide, and written on magnetic tape. The data were played back via the S2 Tape-to-Computer Interface at CRESTech/York University, dedispersed before detection and analyzed. For PSR B1929+10 we found as yet unreported broad microstructure in the average cross-correlation function (CCF) with a characteristic time scale of 90+-10 mcs. On a finer scale PSRs B1133+16 (component II) and B1929+10 show narrow microstructure with a characteristic time scale in the CCFs of 10+-2 mcs and 8+-2 mcs, respectively, the shortest found in the average CCF or autocorrelation function (ACF) for any pulsar, apart perhaps from the Crab pulsar. Histograms of microstructure widths are skewed heavily toward shorter time scales but display a sharp cutoff. The shortest micropulses have widths between 2 and 7 mcs. The time scales of the broad, narrow, and shortest micropulses are, at least partly, related to the widths of the components of the integrated profiles and the subpulse widths. In general, the micropulse modulation index decreases with the micropulse width. No nanopulses or unresolved pulse spikes were detected.

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: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.004
Threshold uncertainty score0.008

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 studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0020.000

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 head0.013
GPT teacher head0.222
Teacher spread0.209 · 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

Citations21
Published2001
Admission routes1
Has abstractyes

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