The Environment of Local Ultraluminous Infrared Galaxies
Bibliographic record
Abstract
The spatial cluster-galaxy correlation amplitude, B gc , is computed for a set of 76 z < 0.3 ultraluminous infrared galaxies (ULIRGs) from the 1 Jy sample. The B gc parameter is used to quantify the richness of the environment within 0.5 Mpc of each ULIRG. We find that the environment of local ULIRGs is similar to that of the field with the possible exceptions of a few objects with environmental densities typical of clusters with Abell richness classes 0 and 1. No obvious trends are seen with redshift, optical spectral type, infrared luminosity, or infrared color ( f 25 / f 60 ). We compare these results with those of local AGNs and QSOs at various redshifts. The 1 Jy ULIRGs show a broader range of environments than local Seyferts, which are exclusively found in the field. The distribution of ULIRG B gc -values overlaps considerably with that of local QSOs, consistent with the scenario where some QSOs go through a ultraluminous infrared phase. However, a rigorous statistical analysis of the data indicates that these two samples are not drawn from the same parent population. The B gc distribution of QSOs shows a distinct tail at high B gc -values, which is not apparent among the ULIRGs. This difference is consistent with the fact that some of the QSOs used for this comparison have bigger and more luminous hosts than the 1 Jy ULIRGs.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| 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) | 0.001 | 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".