<scp>H i</scp> asymmetries in spatially resolved <scp>simba</scp> galaxies
Bibliographic record
Abstract
ABSTRACT We present a study of the neutral atomic hydrogen (H i) content of spatially resolved, low-redshift galaxies in the simba cosmological simulations. We create synthetic H i data cubes designed to match observations from the Apertif Medium-Deep H i imaging survey, and follow an observational approach to derive the H i size–mass relation. The H i size–mass relation for s imba is in broad agreement with the observed relation to within 0.1 dex, but simba galaxies are slightly smaller than expected at fixed H i mass. We quantify the H i spectral ($\rm{A_{\rm{flux}}}$) and morphological ($\rm{A_{\rm{mod}}}$) asymmetries of the galaxies and motivate standardizing the relative spatial resolution when comparing $\rm{A_{\rm{mod}}}$ values in a sample that spans several orders of magnitude in H i mass. Galaxies are classified into three categories (isolated, interacted, or merged) based on their dynamical histories over the preceding $\sim$2 Gyr to contextualize disturbances in their H i reservoirs. We determine that the interacted and merged categories have higher mean asymmetries than the isolated category, with a larger separation between the categories’ $\rm{A_{\rm{mod}}}$ distributions than between their $\rm{A_{\rm{flux}}}$ distributions. For the interacted and merged categories, we find an inverse correlation between baryonic mass and $\rm{A_{\rm{mod}}}$ that is not observed between baryonic mass and $\rm{A_{\rm{flux}}}$. These results, coupled with the weak correlation found between $\rm{A_{\rm{flux}}}$ and $\rm{A_{\rm{mod}}}$, highlight the limitations of only using $\rm{A_{\rm{flux}}}$ to infer the H i distributions of spatially unresolved H i detections.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".