A High‐Resolution Map of<sup>12</sup>CO<i>J</i>= 6–5 Emission in the Starburst Galaxy M82
Bibliographic record
Abstract
We present a map of 12 CO J = 6-5 emission of the nuclear region of the nearby starburst galaxy M82 at resolution 7'' taken with the James Clerk Maxwell Telescope (JCMT). This is the highest resolution map yet available at this transition. A detailed quantitative comparison is made with emission at 12 CO J = 1-0 at the same resolution, yielding new insights into the excitation of molecular gas in this galaxy. The excitation is found to be highest in the central area of the starburst region where the ratio r 61 = 12 CO J = 6-5/ 12 CO J = 1-0 is as high as 0.5, compared to the mean value over the starburst region of 0.24. The excitation ratio peaks along the inner edge of the molecular ring outlined by atomic and molecular gas at lower excitation, and also in two spurs extending northward from the disk toward the outflow associated with the superwind. Emission with higher than average excitation is also found to be associated with the supershell surrounding the luminous SNR candidate 41.9+58, and possibly on a larger scale in gas whose orbits are strongly influenced by the stellar bar. The higher excitation in M82 is likely to be caused predominantly by local increases in kinetic temperature and/or in the geometric filling factor of a preexisting higher excitation component and less likely to be caused by local increases in gas density.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".