Detection of Diffuse Interstellar Bands in the <i>z</i> = 0.5 Damped Lyα System toward AO 0235+164
Bibliographic record
Abstract
We report the first detection of the 5705 and 5780 Å diffuse interstellar bands (DIBs) in a moderate-redshift damped Lyα (DLA) system. We measure a rest-frame equivalent width of 63.2 ± 8.7 mÅ for the 5705 Å feature and 216 ± 9 mÅ for the 5780 Å feature in the z abs = 0.524 DLA toward AO 0235+164 and derive limits for the equivalent widths of the bands at 5797, 6284, and 6613 Å. The equivalent width of the 5780 Å band is lower than would be expected based on the Galactic correlation of DIB strength with N (H I) but is in good agreement with the correlation with E ( B - V ). The relative strengths of the 5780 and 6284 Å DIBs are inconsistent with all Galactic and extragalactic sight lines, except one Small Magellanic Cloud wing sight line toward Sk 143. However, the relative strengths of the 5705 and 5780 Å DIBs are consistent with the Galactic relation, indicating that the relative strengths of these bands may be less sensitive to environment or that they may be associated with a similar carrier. The detection of DIBs at z ~ 0.5 demonstrates that the organic compounds usually assumed to be the band carriers were already present in the universe some 5 Gyr ago.
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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 | 0.001 |
| 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".