[Fe<scp>ii</scp>] and H<sub>2</sub>Filaments in the Supernova Remnant G11.2−0.3: Supernova Ejecta and Presupernova Circumstellar Wind
Bibliographic record
Abstract
We present the results of near-infrared imaging and spectroscopic observations of the young core-collapse supernova remnant (SNR) G11.2-0.3. In the [Fe II] 1.644 μm image, we first discover long, clumpy [Fe II] filaments within the radio shell of the SNR, together with some faint, knotty features in the interior of the remnant. The filaments are thick and roughly symmetric with respect to the northeast-southwest elongation axis of the central pulsar wind nebula. We have detected several [Fe II] lines and a H I Brγ line toward the peak position of the bright southeastern [Fe II] filament. The derived extinction is large ( A V = 13 mag), and it is the brightest [Fe II] 1.644 μm filament detected toward SNRs to date. By analyzing two [Fe II] 1.644 μm images obtained 2.2 yr apart, we detect a proper motion corresponding to an expansion rate of 0.035'' ± 0.013'' yr -1 (830 ± 310 km s -1 ). In addition to the [Fe II] features, we also discover two small H 2 2.122 μm filaments. One is bright and along the southeastern boundary of the radio shell, while the other is faint and just outside its northeastern boundary. We have detected the H 2 (2-1) S (3) line toward the former filament and derive an excitation temperature of 2100 K. We suggest that the H 2 filaments are dense clumps in a presupernova circumstellar wind swept up by the SNR shock, while the [Fe II] filaments are probably composed of both shocked wind material and shocked supernova (SN) ejecta. The distribution of [Fe II] filaments may indicate that the SN explosion in G11.2-0.3 was asymmetric, as in Cassiopeia A. Our results support the suggestion that G11.2-0.3 is a remnant of a SN IIL/b interacting with a dense red supergiant wind.
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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".