Millimeter-wave Searches for Cold Dust and Molecular Gas around T Tauri Stars in MBM 12
Bibliographic record
Abstract
We report results of a sensitive search for cold dust and molecular gas in the disks around eight T Tauri stars in the high-latitude cloud MBM 12. Interferometric observations of 3 mm continuum emission in five fields containing six of the objects and literature values for the remaining two limit the disk masses to M disk < 0.04–0.09 M ⊙ (gas plus dust), for a gas-to-dust mass ratio of 100 and a distance of 275 pc. By co-adding the 3 mm data of our five fields, we set an upper limit to the average disk mass of disk ( N = 5) < 0.03 M ⊙ . Simultaneous observation of the CS J = 2–1 and the N 2 H + 1–0 lines show no emission. Single-dish observations of the 13 CO 2–1 line limit the disk mass to (5–10) × 10 -4 M ⊙ for a standard CO abundance of 2 × 10 -4 . Depletion of CO by up to 2 orders of magnitude through freezing out or photodissociation can reconcile these limits. These mass limits lie within the range found in the Taurus-Auriga and ρ Oph star-forming regions (0.001–0.3 M ⊙ ) and preclude conclusions about possible decrease in disk mass over the 1–2 Myr age range spanned by the latter two regions and MBM 12. Our observations can exclude the presence in MBM 12 of T Tauri stars with relatively bright and massive disks such as T Tau, DG Tau, and GG Tau.
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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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 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".