The z = 0.54 LoBAL Quasar SDSS J085053.12+445122.5. I. Spectral Synthesis Analysis Reveals a Massive Outflow<sup>∗</sup>
Bibliographic record
Abstract
Abstract We introduce SimBAL, a novel spectral-synthesis procedure that uses grids of ionic column densities generated by the photoionization code Cloudy and a Bayesian model calibration to forward-model broad absorption-line quasar (BALQ) spectra. We used SimBAL to analyze the Hubble Space Telescope Cosmic Origins Spectrograph (COS) spectrum of the low-redshift BALQ SDSS J085053.12+445122.5. SimBAL analysis yielded velocity-resolved information about the physical conditions of the absorbing gas. We found that the ionization parameter and column density increase, and the covering fraction decreases, as a function of velocity. The log column density is 22.9 (22.4) (cm−2) for solar (Z = 3 Z ⊙) metallicity. The outflow lies 1–3 pc from the central engine, consistent with the estimated location of the torus. The mass outflow rate is 17–28 M ⊙ yr−1, the momentum flux is consistent with L Bol/c, and the ratio of the kinematic to bolometric luminosity is 0.8%–0.9%. The outflow velocity is similar to the escape velocity at the absorber’s location, and force multiplier analysis indicates that part of the outflow could originate in resonance-line driving. The location near the torus suggests that dust scattering may play a role in the acceleration, although the lack of reddening in this UV-selected object indicates a relatively dust-free line of sight. The low accretion rate (0.06L Edd) and compact outflow suggests that SDSS J0850+4451 might be a quasar past its era of feedback, although since its mass outflow is about eight times the accretion rate, the wind is likely integral to the accretion physics of the central engine.
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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) | 0.002 | 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".