A submillimetre survey for protostellar accretion discs using the JCMT-CSO interferometer
Bibliographic record
Abstract
We present a submillimetre continuum survey for accretion discs around seven embedded protostars in the Perseus and Serpens molecular clouds. Observations were made at frequencies between 339 and 357 GHz using the James Clerk Maxwell Telescope-Caltech Submillimeter Observatory single-baseline interferometer on Mauna Kea, Hawaii. All the objects in our survey show compact dust emission on scales ≲1 arcsec, assumed to arise in a circumstellar accretion disc. We compare the properties of this compact component with evolutionary indicators, such as the ratio of compact to extended emission, and bolometric temperature. We find that discs of mass ∼0.01 M⊙ have formed by the Class 0 stage, and that similar mass discs are observed in Class I and Class II sources. A trend is observed whereby the ratio of compact to extended emission in our sources increases from Class 0 to Class II sources. For three of the objects in the survey, NGC 1333 IRAS2:CR1 and SVS13 in Perseus, and FIRS1 in Serpens, the signal-to-noise ratio is sufficient to allow us to model the brightness distributions with elliptical Gaussian and power-law disc models. The Gaussian fits give semimajor half-power radii of approximately 90 to 140 au, at the assumed distance of 350 pc to the Perseus and Serpens clouds.
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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 | 0.002 | 0.001 |
| 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".