Uncovering the Origins of Fast Radio Bursts Using Local Universe CHIME Discoveries
Bibliographic record
Abstract
Fast radio bursts (FRBs) are one of astronomy's greatest mysteries.These millisecond-duration radio pulses are powerful enough to be observed from distant galaxies and can probe the distribution of ionized baryons throughout the Cosmic Web.However, their origins remain a mystery owing primarily to the small sample of localized FRBs.The Canadian Hydrogen Mapping Experiment (CHIME) telescope, a transit radio interferometric array in Canada, has produced the largest FRB catalog to date.For a fraction of the cataloged bursts, we saved raw voltage data that facilitated their sky localization to sub-arcminute precision.This precision is sufficient to identify the host galaxies of local Universe CHIME FRBs (redshift z < 0.1).In this summary paper, we report on the identification of several nearby FRBs which include the two closest FRBs known to date, FRBs 20200120E and 20181030A.These local Universe bursts have constrained FRB emission mechanisms and progenitor models and have disfavoured many previously held assumptions about the population of FRBs.Finally, we use the local Universe FRBs with known hosts and derive a mean MW halo DM estimate of 32 +16-20 pc cm -3 (95% confidence limit) from a joint Bayesian analysis.
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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 | 0.001 | 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) | 0.002 | 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".