Gas dynamics in an AGN-host galaxy at
Bibliographic record
Abstract
The gas dynamics of galaxies provide critical insights into the evolution of both baryons and dark matter (DM) across cosmic time. In this context, galaxies at cosmic noon, that is, in the period characterized by the most intense star formation and black hole activities, are particularly significant. We present an analysis of the gas dynamics of PKS 0529–549. This galaxy lies at z ≃ 2.6 and hosts a radio-loud active galactic nucleus (AGN). We used new ALMA observations of the [C I] (2−1) line at a spatial resolution of 0.18″ (∼1.5 kpc). We found that (1) the molecular gas forms a rotation-supported disk with Vrot/σv = 6 ± 3 and displays a flat rotation curve out to 3.3 kpc; (2) there are several noncircular components, including a kinematically anomalous structure near the galaxy center, a gas tail to the southwest, and possibly a second weaker tail to the east; and finally, (3) the dynamical estimates of the gas and stellar masses from fitting the rotation curve are inconsistent with photometric estimates made using standard gas conversion factors and stellar population models, respectively. These discrepancies may be due to systematic uncertainties in the photometric masses or in the dynamical masses, or they might be caused by a more massive radio-loud AGN-host galaxy that is hidden behind the gas-rich [C I] emitting starburst galaxy along the line of sight. Our work shows that in-depth investigations of 3D line cubes are crucial for revealing the complexity of gas dynamics in high-z galaxies, in which regular rotation may coexist with noncircular motions and possibly tidal structures.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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".