A session test did not detect peak frequency order in 196 CHIME bursts from FRB 20220912A
We tested the order of peak frequencies in CHIME Catalog 2 bursts from FRB 20220912A. The fixed input release gave 196 accepted events in 46 sessions with at least three events. We compared successive frequency differences with the frequency spread in each session. The mean ratio was 1.985. Its mean under random order is 2. A test with 99,999 shuffles within sessions gave a two-sided p-value of 0.8849. Checks with other event choices and fitted time trends gave the same test decision. The null assumes that the measured frequencies can be exchanged within each session. The median adjacent event separation was 109.4 seconds. Only four pairs had separations at most 0.3 seconds. Thus, this test gives little information about reported subsecond frequency shifts. It does not establish independent source emission. The package includes a saved analysis plan, transformed event data, source code, figures, and simulation checks.
fast radio bursts · FRB 20220912A · CHIME · spectral peak · event order · permutation test · public data
References
6- usesdoi:10.11570/25.0066
We analyze the CHIME/FRB Catalog 2 release 20251231. The package records the file hash.
- usesdoi:10.48550/arXiv.2601.09399
We use the catalog field definitions and the stated limits from the telescope response.
- usesFitted DM rose with fitted peak frequency after daily means were removed from 272 CHIME bursts of FRB 20220912A sci:sha256:cde81a720ef9a991e06bef9a5bbd5b6cce1450a1f5f668310cea80ae43c7c289
This work gave the input address and the event peak definition. We test frequency order with new code.
- doi:10.48550/arXiv.2412.04313
This work reports rapid frequency shifts in close burst pairs. We state why the present sample cannot give a strong test of that effect.
- doi:10.48550/arXiv.2312.07756
This work reports frequency changes in the same source at the Allen Telescope Array.
- doi:10.1214/aoms/1177731677
This is the historical reference for the successive-difference ratio. We give the conditional mean proof used in our test.
Cited by
3 publicationsPublic catalog entries on Sciscape.
- Bounds of three quoted errors plus half a time sample allowed peak spans below 1 ms with a free DM shift in 98 selected CHIME burst fits
Its abstract tests peak-frequency ordering across bursts from FRB20220912A. We test components within bursts.
- Tests within ten-minute blocks did not detect frequency order at 1–100 s gaps in two FRB 20220912A catalogs
This prior test found no session frequency order in CHIME data from the same source. We test a different band and gap range with new code.
- A day reflection test did not detect a short gap time direction in two FAST burst catalogs
This related study tests peak frequency order in a different CHIME catalog. We reuse no code or data.