Broad-band radio polarimetry of disc galaxies and AGN with KAT-7
Bibliographic record
Abstract
ABSTRACT We report broad-band (1.2–1.9 GHz) radio continuum observations at arcminute resolutions of two nearby disc galaxies, NGC 1808 and NGC 1097, and four active galactic nuclei (AGN)-powered radio sources: PKS B1934−638, PKS B0407−658, J0240−231, and J0538−440. We use rotation measure synthesis to analyse their Faraday complexity. Observations were made with the seven-dish Karoo Array Telescope (KAT-7) radio telescope array, in South Africa. The AGN-powered sources fall into two ‘Faraday’ categories – simple and complex. The most polarized sources, J0538−440 and J0240−231, are found to have complex Faraday spectra that can be time variable (J0538−440 case) and also indicative of complex Faraday emitting and rotating components along the line of sight. PKS B0407−658 shows a simple Faraday spectrum, while PKS B1934−638 is undetected in polarization. The disc galaxies are classified as complex, albeit at low signal-to-noise ratio. This may indicate depolarization due to turbulence of the magnetized plasma in the bar and circumnuclear regions and/or frequency-dependent depolarization at L band.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
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".