A PINK update: Improvements to the CELEBI fast radio burst data reduction and analysis pipeline

Fast radio bursts which are well localised to their host galaxy are tools for studying cosmology and the intergalactic medium. The new analysis still awaits peer review, but it already lays out the central claim clearly.

It is relevant because cosmology operates at the edge of what current instruments can measure, where systematic errors and model assumptions are never trivial. Small discrepancies between independent measurements have historically pointed toward missing physics rather than simple calibration errors, and the ongoing tension in the Hubble constant is a live example of how a persistent disagreement between methods can reshape the theoretical landscape. Each new dataset that approaches this territory with independent systematics adds real information to a problem that has resisted easy resolution for more than a decade. Fast radio bursts (FRBs) which are well localised ($<$1") to their host galaxy are tools for studying cosmology and the intergalactic medium. To that end, the CELEBI (CRAFT Effortless Localisation and Enhanced Burst Inspection) pipeline was conceived to enable data reduction from raw antenna voltages to detect fast.

Improvements to the astrometry correction for FRB localisations has aided our ability to determine what part of a galaxy more nearby FRBs have occurred in, which can have its own. We also have implemented time and frequency gating on detected fast transients to enable a boost to signal-to-noise, particularly useful for high dispersion measure or faint fast.

We give examples of our improvements to the localisation, including for the currently 'hostless' FRB 20251019A. Together these updates (named 'Polarisation and astrometry Improvements for New Knowledge', or PINK) greatly improve our ability to keep up with the expected detection rate from.

Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. ArXiv is committed to these values and only works with partners that adhere to them.

The relevance goes beyond one dataset because even small shifts in measured parameters can matter when the field is testing the limits of the standard cosmological model. The Lambda-CDM framework describes the observable universe with remarkable economy, but its success rests on two components, dark matter and dark energy, whose physical nature remains entirely unknown. Any credible measurement that tightens or loosens the constraints on those components moves the entire theoretical enterprise forward, regardless of whether the immediate result looks dramatic on its own terms.

Have an idea for a project that will add value for arXiv's community. Glowacki and 10 other authors View PDF HTML (experimental) Abstract: Fast radio bursts (FRBs) which are well localised ($ Comments: 13 pages, 6 figures.

Because this is still a preprint, the result should be read with genuine interest and proportionate caution. Peer review is not a guarantee of correctness, but it is a process that forces authors to respond to technical criticism from specialists who have no stake in a particular outcome. Preprints that survive that process, often with substantive revisions, emerge with a stronger evidential base than the version that first appeared. Until that stage is complete, the responsible reading keeps uncertainty explicitly visible rather than treating the claims as established findings.

The next step is to see whether the effect survives when independent surveys, different calibration strategies and tighter control of systematic uncertainties enter the picture. Programmes such as Euclid, DESI and the Rubin Observatory will deliver datasets over the next several years that cover the same parameter space with largely independent methods. If the current signal persists through those tests, its theoretical implications will become impossible to set aside. Until peer review and independent follow-up address those open questions, skepticism is not a failure of appreciation for the work; it is part of how science decides what to keep.

Source