Laboratory Simulation of 11-15 μm Spectra Associated with Polycyclic Aromatic Hydrocarbon Molecules
Bibliographic record
Abstract
We have obtained 11-15 μm spectra of thin films of hydrogenated amorphous carbon assembled from carbon nanoparticles. Well-defined, narrow features similar to the interstellar emission bands attributed to polycyclic aromatic hydrocarbons (PAHs) are observed at 11.3, 12, 12.8, 13.5, and 14.2 μm. These features are reproduced in many samples prepared under a variety of conditions, indicating that they involve common molecular components. We suggest that these are based on compact ring structures such as coronene, C 24 H 12 , but that these molecules have peripheral substitutions involving additional aromatic rings. They may also be substituted with sp - or sp 2 -bonded carbon chains. All bands exhibit slight energy shifts in different samples in response to changes in preparation conditions. These shifts replicate variations in wavelength and profile of the 11-15 μm bands seen in different type of emission source. None of the nanoparticle samples exhibit all of the 11.3, 12, 12.8, 13.5, and 14.2 μm features. This implies that the interstellar bands are produced by a limited variety of PAH structures, rather than by a single dominant species.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".