Automated radio follow-up for fast radio bursts with an application to a hyperactive repeating source, FRB 20220912A
Bibliographic record
Abstract
Fast radio bursts (FRBs) are brief (µs – ms), energetic astrophysical events originating from extra-galactic sources with unknown physical origins. Constraining the progenitor of FRBs can better our understanding of stellar evolution and rates of core collapse supernova. Many progenitor models predict rapid multi-wavelength or multi-messenger counterparts, thus coordinated real-time follow-up is crucial to constraining these models. frb-voe is a publicly available software package that enables radio observatories to broadcast fast radio burst (FRB) alerts to subscribers through low-latency virtual observatory events (VOEvents). This thesis describes a use-case of frb-voe by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) Collaboration, which has broadcast thousands of FRB alerts to subscribers worldwide. Using this service, observers have daily opportunities to conduct rapid multi-wavelength follow-up observations of new FRB sources. Alerts are distributed as machine-readable reports and as emails containing FRB metadata, and are available to the public within approximately 13 seconds of detection. The frb-voe service can act as a foundation on which any observatory that detects FRBs can build its own VOEvent broadcasting service to contribute to the coordinated multi-wavelength follow-up of astrophysical transients. This thesis also describes an example follow-up of FRB 20220912A. This FRB is a highly active repeating FRB source, discovered by the CHIME radio telescope using the real-time FRB detection system and subsequently localized by the Deep Synoptic Array-110 (DSA-110) through VOEvents. Radio follow-up revealed the source displays interesting properties, such as “microshots”, a drifting time-variable central emitting frequency, and indications of variations of its dispersion measure (DM). We present results from a long-term radio follow-upcampaign of FRB 20220912A using over 200 hours of data collected by the CHIME Pulsar backend, spanning the 2 years following the source’s discovery. The CHIME/Pulsar backend uses a digitally-formed tracking beam to observe the source for 21 minutes daily at 41 us time resolution between 400-800 MHz. This study finds 828 bursts from the source, which test the energetics of some FRB progenitor models, and we show strong evidence for a variation in the source’s DM. We discuss the implications of the newly discovered DM variation and implications of the energetics regarding the physical origins of the source
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 0.003 |
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".