Evidence for Shocked Molecular Gas in the Galactic Supernova Remnant CTB 109 (G109.1-1.0)
Bibliographic record
Abstract
We report the detection of molecular clouds around the X-ray-bright interior feature in the Galactic supernova remnant (SNR) CTB 109 (G109.1-1.0). This feature, called the "lobe," has been previously suggested to be the result of an interaction of the SNR shock wave with a molecular cloud complex. We present new high-resolution X-ray data from the Chandra X-Ray Observatory and new high-resolution CO data from the Five College Radio Astronomy Observatory that show the region of interaction with the cloud complex in greater detail. The CO data reveal three clouds around the lobe in the velocity interval -57 km s -1 < v < -52 km s -1 . The velocity profiles of 12 CO in various parts of the east cloud are well fit with a Gaussian; however, at the position at which the CO cloud and the lobe overlap, the velocity profile has an additional component toward higher negative velocities. The molecular hydrogen density in this part of the cloud is relatively high ( N ≈ 1.9 × 10 20 cm -2 ), whereas the foreground absorption in X-rays ( N H ≈ 4.5 × 10 21 cm -2 ), obtained from Chandra data, is lower than in other parts of the cloud and in the north and south clouds. These results indicate that the east cloud has been hit by the SNR blast wave on the western side, forming the bright X-ray lobe.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.010 | 0.003 |
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".