A deep search for diffuse interstellar band 4430 Å in the circumgalactic medium
Bibliographic record
Abstract
ABSTRACT We investigate the absorption signals of one of the strongest diffuse interstellar bands, DIB$\lambda 4430$, in the circumgalactic medium (CGM) traced by Mg ii absorption lines. To this end, we make use of approximately 60 000 Mg ii absorption line spectra within $0.4 < z < 1.0$ compiled from the Sloan Digital Sky Surveys and obtain composite spectra with uncertainties for absorption line measurements being a few mÅ. By using Mg ii absorption strength and dust reddening relation from the literature, we measure the DIB$\lambda 4430$ absorption strength as a function of E(B – V) in the CGM, and compare the Milky Way DIB$\lambda 4430$ –E(B – V) relation extrapolated down to the CGM E(B – V) region. Our results show no detectable signals of DIB$\lambda 4430$ across the entire E(B – V) range in the CGM traced by Mg ii absorption lines. This lack of detection of DIB$\lambda 4430$ in the CGM is inconsistent with the Milky Way signals by $\sim 5 \, \sigma$, indicating that the factors associated with different environments affect the abundance of the DIB$\lambda 4430$ carrier.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 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".