The magnetar model's energy crisis for a prolific repeating fast radio burst source

TL;DR

This study presents an extensive burst dataset from FRB 20240114A, revealing its energy output surpasses the magnetic energy of a typical magnetar, challenging existing models of FRB origins.

Contribution

It provides the largest single-source burst sample and demonstrates that the energy released exceeds the magnetar energy budget, suggesting the need for revised models or more powerful engines.

Findings

Detected 11,553 bursts over 214 days from a single FRB source.

Total energy exceeds 86% of a magnetar's magnetic energy.

Energy output surpasses known repeaters, challenging current models.

Abstract

Fast radio bursts (FRBs) are widely considered to originate from magnetars that power the explosion through releasing magnetic energy. Active repeating FRBs have been seen to produce hundreds of bursts per hour and can stay active for months, thus may provide stringent constraints on the energy budget of FRBs' central engine. Within a time span of 214 days, we detected 11,553 bursts from the hyper-active FRB 20240114A that reached a peak burst rate of 729 hr$^{-1}$. This is the largest burst sample from any single FRB source, exceeding the cumulative total of all published bursts from all known FRBs to date. Assuming typical values of radio efficiency and beaming factor, the estimated total isotropic burst energy of this source exceeds 86% of the dipolar magnetic energy of a typical magnetar. The total released energy from this source exceeds that of other known repeaters by about one and a half orders of magnitude, yielding the most stringent lower limit of $4.7\times10^{32}$ G cm$^3$ for the magnetar's magnetic moment. The source remained active at the end of this observation campaign. Our findings thus require either the FRB's central magnetar engine's possessing exceptionally high emission efficiency or a more powerful compact object than a typical magnetar.