A catalogue of absorption lines in eight Hubble Space Telescope/STIS E230M 1.0 < z < 1.7 quasar spectra★
Bibliographic record
Abstract
We have produced a catalogue of line identifications and equivalent width measurements for all absorption features in eight ultraviolet echelle quasar spectra. These spectra were selected as having the highest signal-to-noise ratio among the Hubble Space Telescope/STIS spectra obtained with the E230M grating. We identify 56 metal-line systems towards the eight quasars, and present plots of detected transitions, aligned in velocity space. We found that about 1/4–1/3 of the features in the Lyα forest region, redward of the incidence of the Lyβ forest, are metal lines. High-ionization transitions are common. At the redshift range we study, z < 1.7, we see both O vi and C iv in 88–90 per cent of the metal-line systems for which the spectra cover the expected wavelength. Si iii is seen in 58 per cent, while low-ionization absorption in C ii, Si ii and/or Al ii is detected in 50 per cent of the systems for which they are covered. This catalogue will facilitate future studies of the Lyα forest and of metal-line systems of various types.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.009 | 0.005 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.011 | 0.006 |
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".