CHIMPS2: 13CO <i>J</i> = 3→2 emission in the central molecular zone
Bibliographic record
Abstract
ABSTRACT We present the initial data for the $(J = 3 \rightarrow 2)$ transition of $^{13}\text{CO}$ obtained from the central molecular zone (CMZ) of the Milky Way as part of the CO Heterodyne Inner Milky Way Plane Survey 2 (CHIMPS2). Covering $359^{\circ } \le l \le 1^{\circ }$ and $|b| \le 0.5^{\circ }$ with an angular resolution of 19 arcsec, velocity resolution of 1 km s$^{-1}$, and rms $\Delta {T_{\rm A}^{*}} = 0.59\, \mathrm{K}$ at these resolutions, our observations unveil the complex structure of the CMZ molecular gas in improved detail. Complemented by the $\rm {^{12}CO}$ CHIMPS2 data, we estimate a median optical depth of $\tau _{13} = 0.087$. The preliminary analysis yields a median $^{13}\text{CO}$ column-density range equal to $N(^{13}{\rm CO}) = 2{\!-\!}5 \times 10^{18}\, \mathrm{cm}^{-2}$, median H$_{2}$ column density equal to $N(\mathrm{H_{2}}) = 4 \times 10^{22}\, \mathrm{cm}^{-2}$ to $1 \times 10^{23}\, \mathrm{cm}^{-2}$. We derive $N({\rm H_{2}})$-based total mass estimates of $M({\rm H}_{2}) = 2{\!-\!}6 \times 10^{7}\, \mathrm{M}_{\odot }$, in agreement with previous studies. We analyse the relationship between the integrated intensity of $^{13}\text{CO}$ and the surface density of compact sources identified by Herschel Hi-GAL, and find that younger Hi-GAL sources detected at 500 $\rm{\mu m}$ but not at 70 $\rm{\mu m}$ follow the dense gas of the CMZ more closely than those that are bright at 70 $\rm{\mu m}$. The latter, actively star-forming sources appear to be more associated with material in the foreground spiral arms.
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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 | 0.001 |
| 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".