Formation of Minigalaxies in Defunct Cosmological H<scp>ii</scp>Regions
Bibliographic record
Abstract
Using a large set of high-resolution numerical simulations incorporating nonequilibrium molecular hydrogen chemistry and a constant source of external radiation, we study gas collapse in previously photoionized minigalaxies with virial temperatures less than 10 4 K in the early universe (redshifts z = 10-20). We confirm that the mechanism of positive feedback of ionizing radiation on star formation in minigalaxies proposed by Ricotti and coworkers can be efficient despite a significant flux of metagalactic photodissociating radiation. We derive critical fluxes for the Lyman-Werner background radiation sufficient to prevent the collapse of gas in minigalaxies as a function of the virial mass of the halo and redshift. In our model, the formation of minigalaxies in defunct H II regions is most efficient at large redshifts ( z ≳ 15) and/or for large local gas overdensity δ ≳ 10. We show that nonequilibrium chemistry plays an important dynamical role not only during the initial evolutionary phase, leading to the gas becoming gravitationally unstable inside the minihalo, but also at the advanced stages of the core collapse, resulting in efficient gas accretion in the core region. We speculate on a possible connection between our objects and metal-poor globular clusters and dwarf spheroidal galaxies.
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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 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".