Absolute Calibration of Diffuse Radio Surveys at 45 and 150 MHz
Bibliographic record
Abstract
Abstract We use measurements from the Experiment to Detect the Global EoR Signature (EDGES) to determine scale and zero-level corrections to the diffuse radio surveys by Guzmán et al. at 45 MHz and by Landecker & Wielebinski at 150 MHz. We find that the map of Guzmán et al. requires a scale correction of 1.076 ± 0.034 (2 σ ) and a zero-level correction of −160 ± 78 K (2 σ ) to best-fit the EDGES data. For the map of Landecker & Wielebinski, the scale correction is 1.112 ± 0.023 (2 σ ) and the zero-level correction is 0.7 ± 6.0 K (2 σ ). The correction uncertainties are dominated by systematic effects, of which the most significant are uncertainty in the calibration of the EDGES receivers, antenna pointing, and tropospheric and ionospheric effects. We propagate the correction uncertainties to estimate the uncertainties in the corrected maps themselves and find that the 2 σ uncertainty in the map brightness temperature is in the range 3.2%–7.5% for the map of Guzmán et al. and 2.1%–9.0% for the map of Landecker & Wielebinski, with the largest percentage uncertainties occurring at high Galactic latitudes. The corrected maps could be used to improve existing diffuse low-frequency radio sky models, which are essential tools in analyses of cosmological 21 cm observations, as well as to investigate the existence of a radio monopole excess above the cosmic microwave background and known Galactic and extragalactic contributions.
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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 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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 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".