High-Resolution Images of CO [ITAL]J[/ITAL] = 2–1 Emission from the Carbon Star V Cygni
Bibliographic record
Abstract
This paper presents observations of the CO J = 2–1 emission from the circumstellar envelope of the mass-losing carbon star V Cyg. The observations were made with the Caltech Millimeter Array. A previously published single-dish map was used to construct short-spacing visibilities not sampled by the interferometer data, thereby recovering missing flux in extended low brightness emission. The images have an angular resolution of ∼1 2 with a velocity resolution of 1 MHz (1.3 km s -1 ). The channel maps are consistent with an expanding envelope that is roughly spherical, but they also show evidence for asymmetric structure, as well as small-scale clumping. We compare these observations, as well as other published spectra, with statistical equilibrium models for CO in a circumstellar envelope. Models that fit the spherically averaged data must invoke a mass-loss rate, , that has decreased with time by a factor of ∼2–3 over the past several hundred years. The model kinetic temperature structure in radius, T K ( r ), decreases as r -0.8 out to r ≈ 6 × 10 15 cm and levels off to a constant value at T K = 23 K beyond. The secular change in may be related to changes in the stellar luminosity or temperature, as predicted by recent numerical hydrodynamic models for mass loss. The inferred kinetic temperature structure suggests that heating by the photoelectric effect on dust grains is important in the outer envelope.
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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 | 0.000 | 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".