Bibliographic record
Abstract
The Cygnus Loop is one of the nearest supernova remnants (440 pc), allowing studies of spatial variations to be carried out at high physical resolution compared with other supernova remnants. Chandra Advanced CCD Imaging Spectrometer (ACIS) observations were obtained covering the bright V-shaped region on the south-west limb. This region has strong 0.2–2 keV spectral variations seen with the ROSAT Position Sensitive Proportional Counter. The nature of the spectral variations is analysed using the ACIS observations. It is found that temperature, abundance variations and column density variations all have a significant contribution to the observed spectral variations. Fits with C, N, O (O group) elements and Ne, Na, Mg, Al, Si, S, Ar (Ne group) elements varied together are better than fits with just O and Ne varied. Large spatial variations in abundances are seen, yet the Ne group to O group ratio and the Fe group (Ca, Fe, Ni) to O group ratio are nearly constant for all of the spectra. The most natural explanation is that the elements in the region are due to supernova explosion of a star of ∼18 M⊙ which predated the Cygnus Loop explosion.
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 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".