Discovery of a Bipolar Outflow from 2MASSW J1207334-393254, a 24 <i>M</i> <sub>Jup</sub> Brown Dwarf
Bibliographic record
Abstract
The 24 M Jup brown dwarf 2MASS 1207-3932 has for some time been known to show clear signs of classical T Tauri-like accretion. Through analysis of its oxygen forbidden emission, we have discovered that it is driving a bipolar outflow. Blue- and redshifted components to the [O I] λ6300 forbidden emission line are seen at velocities of -8 and +4 km s -1 (on either side of the systemic velocity). Spectroastrometry recovers the position of both components relative to the brown dwarf at ~0.08'' (in opposing directions). A position-velocity diagram of the line region supports the spectroastrometric results. The Hα and He I λ6678 lines were also analyzed. These line regions are not offset with respect to the continuum, ruling out the presence of spectroastrometric artifacts and underlining the validity of the [O I] λ6300 results. The low radial velocity of the outflow and the relatively large offsets are consistent with 2MASS 1207-3932 having a near edge-on disk as proposed by Scholz et al. 2MASS 1207-3932 is now the smallest mass galactic object known to drive an outflow. The age of the TW Hydrae association (~8 Myr) also makes this one of the oldest objects with a resolved jet. This discovery not only highlights the robustness of the outflow mechanism over an enormous range of masses but also suggests that it may even be feasible for young giant planets with accretion disks to drive outflows.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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".