The effect of the intergalactic environment on the observability of Lyα emitters during reionization
Bibliographic record
Abstract
Observations of high-redshift Lyα sources are a major tool for studying the high-redshift universe and are one of the most promising ways to constrain the later stages of reionization. The understanding and interpretation of the data is far from straightforward, however. We discuss the effect of the reionizing intergalactic medium (IGM) on the observability of Lyα sources based on large simulations of early structure formation with radiative transfer. This takes into account self-consistently the reionization history, density, velocity and ionization structures and non-linear source clustering. We find that all fields are highly anisotropic and as a consequence there are very large variations in opacity among the different lines of sight. The velocity effects, from both infall and source peculiar velocity are most important for the luminous sources, affecting the line profile and depressing the bright end of the luminosity function. The line profiles are generally asymmetric and the line centres of the luminous sources are always absorbed due to the high density of the local IGM. For both luminous and average sources the damping wing effects are of similar magnitude and remain significant until fairly late, when the IGM is ionized between 30 and 70 per cent by mass. The ionizing flux in the ionized patch surrounding a high-density peak is generally strongly dominated, particularly at late times, by the cluster of faint sources, rather than the central massive galaxy. Our results reproduce well the observed mean opacity of the IGM at z∼ 6. The IGM absorption does not change appreciably the correlation function of sources at high redshift. Our derived luminosity function assuming constant mass-to-light ratio provides an excellent match to the shape of the observed luminosity function at z= 6.6 with faint-end slope of α=−1.5. The resulting mass-to-light ratio implies that the majority of sources responsible for reionization are too faint to be observed by the current surveys.
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 | 0.001 | 0.003 |
| 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 | 0.001 | 0.001 |
| 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".