ASSIGNMENT OF 5069 Å DIFFUSE INTERSTELLAR BAND TO HC <sub>4</sub> H <sup>+</sup> : DISAGREEMENT WITH LABORATORY ABSORPTION BAND
Bibliographic record
Abstract
Krełowski et al. have reported a weak, diffuse interstellar band (DIB) at 5069 Å which appears to match in both mid-wavelength and width the A 2 Π u – X 2 Π g gas-phase origin absorption band of HC 4 H + . Here, we present laboratory rotational profiles at low temperatures which are then compared with the 5069 Å DIB using ∼0.1 and 0.3 Å line widths based on a realistic line-of-sight interstellar velocity dispersion. Neither the band shape nor the wavelength of the maximum absorption match, which makes the association of the 5069 Å DIB with HC 4 H + unlikely. The magnetic dipole transition X 2 Π g Ω = 1/2→ X 2 Π g Ω = 3/2 within the ground electronic state which competes with collisional excitation is also considered. In addition, we present the laboratory gas-phase spectrum of the A 2 Π u – X 2 Π g transition of HC 4 H + measured at 25 K in an ion trap and identify further absorption bands at shorter wavelengths for comparison with future DIB data.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".