The Supernova Remnant CTB 104A: Magnetic Field Structure and Interaction with the Environment
Bibliographic record
Abstract
We present new, high-resolution 1420 and 408 MHz continuum images and H I and 12 CO ( J = 1-0) spectral line maps of the diffuse supernova remnant (SNR) CTB 104A (G93.7-0.3). Analysis of the complex continuum emission reveals no significant spectral index variations across the remnant. Three prominences around CTB 104A are found to be related to the SNR, while one extension to the east is identified as an H II region associated with a background molecular shell. Small-scale polarization and rotation measure (RM) structures are turbulent in nature, but we find a well-ordered RM gradient across the remnant, extending from southeast to northwest. This gradient does not agree with the direction of the global Galactic magnetic field but does agree with a large-scale RM anomaly inferred from RM data by Clegg et al. We show that the observed morphology of CTB 104A is consistent with expansion in a uniform magnetic field, and this is supported by the observed RM distribution. By modeling the RM gradient with a simple compression model we have determined the magnetic field strength within the remnant as B 0 ≈ 2.3 μG. We have identified signatures of the interaction of CTB 104A with the surrounding neutral material and determined its distance, from the kinematics of the H I structure encompassing the radio emission, as 1.5 kpc. We also observed clear breaks in the H I shell that correspond well to the positions of two of the prominences, indicating regions where hot gas is escaping from the interior of the SNR.
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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 | 0.000 |
| 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) | 0.001 | 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".