Polarized Emission from Four Supernova Remnants in the THOR Survey
Bibliographic record
Abstract
Abstract We present polarization and Faraday rotation for the supernova remnants (SNRs) G46.8 − 0.3, G43.3 − 0.2, G41.1 − 0.3, and G39.2 − 0.3 in the L-band (1–2 GHz) radio continuum in the H i/OH/Recombination line survey. We detect polarization from G46.8 − 0.3, G43.3 − 0.2, and G39.2 − 0.3 but find upper limits at the 1% level of Stokes I for G41.1 − 0.3. For G46.8 − 0.3 and G39.2 − 0.3, the fractional polarization varies on small scales from 1% to ∼6%. G43.3 − 0.2 is less polarized with fractional polarization ≲3%. We find upper limits at the 1% level for the brighter regions in each SNR with no evidence for associated enhanced Faraday depolarization. We observe significant variation in Faraday depth and fractional polarization on angular scales down to the resolution limit of 16″. Approximately 6% of our polarization detections from G46.8 − 0.3 and G39.2 − 0.3 exhibit two-component Faraday rotation and 14% of polarization detections in G43.3 − 0.2 are multicomponent. For G39.2 − 0.3, we find a bimodal Faraday depth distribution with a narrow peak and a broad peak for all polarization detections as well as for the subset with two-component Faraday rotation. We identify the narrow peak with the front side of the SNR and the broad peak with the back side. Similarly, we interpret the observed Faraday depth distribution of G46.8 − 0.3 as a superposition of the distributions from the front side and the back side. We interpret our results as evidence for a partially filled shell with small-scale magnetic field structure and internal Faraday rotation.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot 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.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".