Which astrophysical objects produce fast radio bursts?
In plain words
One magnetar in our own galaxy (a neutron star with a magnetic field of about $2e14\ \mathrm{G}$) has emitted an FRB-like burst, but it is unknown whether magnetars make all FRBs. Bursts also come from an old star cluster and from dead galaxies, where young magnetars should be rare.
Precise statement
Given the observed FRB population (all-sky rate of order $1e3\,\text{per day}$ above a few Jy ms at $600\,\mathrm{MHz}$, isotropic energies $1e36 \text{ to } 1e43\,\mathrm{erg}$, hosts ranging from star-forming spirals to quiescent ellipticals and a globular cluster of M81), determine which source classes produce it and in what proportions. An answer is a population model (young magnetars, merger-formed or accretion-induced neutron stars, accreting compact binaries, other) that reproduces the energy function, repetition statistics, and host and offset distributions.
What would settle it
A census of several hundred FRBs localized to parsec-scale environments, combined with X-ray or optical counterparts that fix the progenitor class of individual sources.
Status in the literature
Unverified note
2025: CHIME Outriggers localized the brightest one-off burst, FRB 20250316A, to a 13 pc region in NGC 4141, where JWST found a faint candidate counterpart consistent with a red giant or a massive star.
Related problems
- More general than Do all fast radio burst sources eventually repeat?
- More general than How do FRB sources arise in old stellar populations?
- More general than Origin of periodic activity windows in repeating FRB sources