The SCUBA-2 Cosmology Legacy Survey: blank-field number counts of 450-mu m-selected galaxies and their contribution to the cosmic infrared background
Bibliographic record
Abstract
The first deep blank-field 450 μm map (1σ ≈ 1.3 mJy) from the Submillimetre Common-User Bolometer Array-2 SCUBA-2 Cosmology Legacy Survey (S2CLS), conducted with the James Clerk Maxwell Telescope (JCMT) is presented. Our map covers 140 arcmin[Superscript: 2] of the Cosmological Evolution Survey field, in the footprint of the Hubble Space Telescope (HST) Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey. Using 60 submillimetre galaxies detected at ≥3.75σ, we evaluate the number counts of 450-μm-selected galaxies with flux densities S[Subscript: 450] > 5 mJy. The 8 arcsec JCMT beam and high sensitivity of SCUBA-2 now make it possible to directly resolve a larger fraction of the cosmic infrared background (CIB, peaking at λ ∼ 200 μm) into the individual galaxies responsible for its emission than has previously been possible at this wavelength. At S[Subscript: 450] > 5 mJy, we resolve (7.4 ± 0.7) × 10[Superscript: −2] MJy sr[Superscript: −1] of the CIB at 450 μm (equivalent to 16 ± 7 per cent of the absolute brightness measured by the Cosmic Background Explorer at this wavelength) into point sources. A further ∼40 per cent of the CIB can be recovered through a statistical stack of 24 μm emitters in this field, indicating that the majority (≈60 per cent) of the CIB at 450 μm is emitted by galaxies with S[Superscript: 450] > 2 mJy. The average redshift of 450 μm emitters identified with an optical/near-infrared counterpart is estimated to be 〈z〉 = 1.3, implying that the galaxies in the sample are in the ultraluminous class (LIR≈1.1×10[Superscript: 12]L⊙LIR≈1.1×10[Superscript: 12]L[Subscript: ⊙]). If the galaxies contributing to the statistical stack lie at similar redshifts, then the majority of the CIB at 450 μm is emitted by galaxies in the luminous infrared galaxy (LIRG) class with L[Subscript: IR] > 3.6 × 10[Superscript: 11] L[Subscript: ⊙].
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| 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 teacher head, 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".