Low-amplitude clustering in low-redshift 21-cm intensity maps cross-correlated with 2dF galaxy densities
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
We report results from 21-cm intensity maps acquired from the Parkes radio telescope and cross-correlatedwith galaxy maps from the 2dF galaxy survey. The data span the redshift range 0.057 <z <0.098 and cover approximately 1300 deg(2) over two long fields. Cross-correlation is detected at a significance of 5.7 sigma. The amplitude of the cross-power spectrum is low relative to the expected dark matter power spectrum, assuming a neutral hydrogen (H-I) bias andmass density equal to measurements from the ALFALFA survey. The decrement is pronounced and statistically significant at small scales. At k similar to 1.5 h Mpc(-1), the cross-power spectrum is more than a factor of 6 lower than expected, with a significance of 15.3 sigma. This decrement indicates a lack of clustering of neutral hydrogen (H-I), a small correlation coefficient between optical galaxies and H-I, or some combination of the two. Separating 2dF into red and blue galaxies, we find that red galaxies are much more weakly correlated with H-I on k similar to 1.5 h Mpc(-1) scales, suggesting that H-I is more associated with blue star-forming galaxies and tends to avoid red galaxies.
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.
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 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 it