The Spatial Distribution of Metals in the Intergalactic Medium
Bibliographic record
Abstract
We investigate the impact of environment on the metallicity of the diffuse intergalactic medium. We use pixel correlation techniques to search for weak C IV and O VI absorption in the spectrum of quasar Q1422+231 in regions of the spectrum close to and far from galaxies at z ~ 3. This is achieved both by using the positions of observed Lyman-break galaxies and by using strong C IV absorption as a proxy for the presence of galaxies near the line of sight. We find that the metal line absorption is a strong function of not only the H I optical depth, and thus gas density, but also proximity to highly enriched regions, and so proximity to galaxies. The parameter "proximity to galaxies" can account for some, but not all, of the scatter in the strength of C IV absorption for fixed H I. Finally, we find that even if we limit our analysis to the two-thirds of the pixels that are at least 600 km s -1 from any C IV line that is strong enough to detect unambiguously (τ > 0.1), our statistical analysis reveals only slightly less C IV for fixed H I than when we analyze the whole spectrum. We conclude that while the metallicity is enhanced in regions close to (Lyman-break) galaxies, the enrichment is likely to be much more widespread than their immediate surroundings.
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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 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| 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".