Ubiquitous Molecular Outflows in z > 4 Massive, Dusty Galaxies. I. Sample Overview and Clumpy Structure in Molecular Outflows on 500 pc Scales
Bibliographic record
Abstract
Massive galaxy-scale outflows of gas are one of the most commonly-invoked\nmechanisms to regulate the growth and evolution of galaxies throughout the\nuniverse. While the gas in outflows spans a large range of temperatures and\ndensities, the cold molecular phase is of particular interest because molecular\noutflows may be capable of suppressing star formation in galaxies by removing\nthe star-forming gas. We have conducted the first survey of molecular outflows\nat z > 4, targeting 11 strongly-lensed dusty, star-forming galaxies (DSFGs)\nwith high-resolution Atacama Large Millimeter Array (ALMA) observations of OH\n119um absorption as an outflow tracer. In this first paper, we give an overview\nof the survey, focusing on the detection rate and structure of molecular\noutflows. We find unambiguous evidence for outflows in 8/11 (73%) galaxies,\nmore than tripling the number known at z > 4. This implies that molecular winds\nin z > 4 DSFGs must have both a near-unity occurrence rate and large opening\nangles to be detectable in absorption. Lensing reconstructions reveal that\n500pc-scale clumpy structures in the outflows are common. The individual clumps\nare not directly resolved, but from optical depth arguments we expect that\nfuture observations will require 50-200pc spatial resolution to do so. We do\nnot detect high-velocity [CII] wings in any of the sources with clear OH\noutflows, indicating that [CII] is not a reliable tracer of molecular outflows.\nOur results represent a first step toward characterizing molecular outflows at\nz > 4 at the population level, demonstrating that large-scale outflows are\nubiquitous among early massive, dusty 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 | 0.000 |
| Bibliometrics | 0.004 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".