Spatially-resolved relation between [C <scp>i</scp>] 3<i>P</i>1–3<i>P</i>0 and 12CO (1–0) in Arp 220
Bibliographic record
Abstract
Abstract We present $\sim {0.^{\prime \prime }3}$ (114 pc) resolution maps of [C i] 3P1–3P0 (hereafter [C i] (1–0)) and 12CO (1–0) obtained toward Arp 220 with the Atacama Large Millimeter/submillimeter Array. The overall distribution of the [C i] (1–0) emission is consistent with the CO (1–0). While the [C i] (1–0) and CO (1–0) luminosities of the system follow the empirical linear relation for the unresolved ULIRG sample, we find a sublinear relation between [C i] (1–0) and CO (1–0) using the spatially-resolved data. We measure the [C i] (1–0)$/$CO (1–0) luminosity ratio per pixel in star-forming environments of Arp 220 and investigate its dependence on the CO (3–2)$/$CO (1–0) ratio (RCO). On average, the [C i] (1–0)$/$CO (1–0) luminosity ratio is almost constant up to RCO ≃ 1 and then increases with RCO. According to the radiative transfer analysis, a high C i$/$CO abundance ratio is required in regions with high [C i] (1–0)$/$CO (1–0) luminosity ratios and RCO > 1, suggesting that the C i$/$CO abundance ratio varies at ∼100 pc scale in Arp 220. The [C i] (1–0)$/$CO (1–0) luminosity ratio depends on multiple factors and may not be straightforward to interpret. We also find the high-velocity components traced by [C i] (1–0) in the western nucleus, likely associated with the molecular outflow. The [C i] (1–0)$/$CO (1–0) luminosity ratio in the putative outflow is 0.87 ± 0.28, which is four times higher than the average ratio of Arp 220. While there is a possibility that the [C i] (1–0) and CO (1–0) emission traces different components, we suggest that the high line ratios are likely to be because of elevated C i$/$CO abundance ratios based on our radiative transfer analysis. A C i-rich and CO-poor gas phase in outflows could be caused by the irradiation of the cosmic rays, the shock heating, and the intense radiation field.
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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 | 0.001 |
| 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) | 0.001 | 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".