Optical Identification of 15$\mu $m Sources in the AKARI Performance Verification Field toward the North Ecliptic Pole
Bibliographic record
Abstract
Abstract We present the results of optical identifications for 257 mid-infrared sources detected with a deep 15$\;\mu$m survey over approximately 80 arcmin$^2$ area in the AKARI performance verification field near the North Ecliptic Pole. The 15$\;\mu$m fluxes of the sources range from 1 mJy down to 40 $\mu $Jy, approximately one half of which are below 100 $\mu $Jy. Optical counterparts were searched for within a 2$^{\prime\prime}$-3$^{\prime\prime}$ radius in both the $BVRi'z'$ catalog generated by using the deep Subaru/Suprime-cam field, which covers one-third of the performance verification field, and the $g'r'i'z'$ catalog based on observations made with MegaCam at CFHT. We found that the $B-R$ and $R-z'$ colors of sources with successful optical identifications are systematically redder than that of the entire optical sample in the same field. Moreover, approximately 40% of the 15$\;\mu$m sources show colors with $R-$L15$\gt$ 5, which cannot be explained by the spectral energy distribution (SED) of normal quiescent spiral galaxies, but are consistent with SEDs of redshifted ($z\gt1$) starburst or ultraluminous infrared galaxies. This result indicates that the fraction of the ultraluminous infrared galaxies in our faint 15$\;\mu$m sample is much larger than that in our brighter 15$\;\mu$m sources, which is consistent with the evolving mid-infrared luminosity function derived by recent studies based on Spitzer 24$\;\mu$m deep surveys. Based on an SED fitting technique, the nature of the faint 15$\;\mu$m sources is further discussed for a selected number of sources with available $K_{\rm s}$-band data.
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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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 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".