The Properties of the X-Ray-selected EMSS Sample of BL Lacertae Objects
Bibliographic record
Abstract
We present updated and complete radio, optical, and X-ray data for BL Lac objects in the Einstein Medium Sensitivity Survey (EMSS). The complete "M91" sample first presented in Morris et al. is updated to include 26 BL Lac objects in total, and we define a new, virtually complete sample consisting of 41 EMSS BL Lac objects (the "D40" sample). New high signal-to-noise ratio, arcsecond-resolution VLA observations are also presented for 11 EMSS BL Lac objects, completing VLA observations of the M91 sample. The addition of four new objects, as well as updated X-ray flux and redshift information, has increased the ⟨ V e / V a ⟩ value for the M91 sample to 0.399 ± 0.057 and ⟨ V e / V a ⟩ = 0.427 ± 0.045 for the newly defined D40 sample. In conjunction with other studies of X-ray–selected BL Lac (XBL) samples, these results solidify negative evolution for XBLs, especially for more extreme high-energy–peaked BL Lac objects, for which we find ⟨ V e / V a ⟩ = 0.271 ± 0.077. The observed ⟨ V e / V a ⟩, spectral, and radio properties of XBLs are completely consistent with being the beamed population of low-luminosity, FR-1 radio galaxies. However, our VLA observations do confirm that XBLs are too core dominated to be consistent with a beamed population of FR-1's seen at intermediate angles, as suggested by the unified model, if XBLs have moderate outflow velocities (γ ∼ 5).
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.001 |
| 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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".