A repeating fast radio burst source in a globular cluster

Monday 6 Jun 2022, 13:30 → 13:50 Europe/Rome

0/0-3 - Sala Rosino (Dipartimento di Fisica e Astronomia - Edificio ex-Rizzato)

Speakers: Amelia Vietri (Università degli Studi di Padova)

Fast radio bursts (FRBs) are exceptionally luminousflashes of unknown physical origin, reaching us fromother galaxies1. Most FRBs have only ever been seenonce, while others flash repeatedly, though sporadi-cally2,3. Many models invoke magnetically poweredneutron stars (magnetars) as the engines producingFRB emission4,5. Recently, CHIME/FRB announcedthe discovery6of the repeating FRB 20200120E, com-ing from the direction of the nearby grand design spi-ral galaxy M81. Four potential counterparts at otherobserving wavelengths were identified6but no defini-tive association with these sources, or M81, could bemade. Here we report an extremely precise localisa-tion of FRB 20200120E, which allows us to associate itwith a globular cluster (GC) in the M81 galactic sys-tem and to place it≈2 pc offset from optical center oflight of the GC. This confirms6that FRB 20200120Eis 40 times closer than any other known extragalacticFRB. Because such GCs host old stellar populations,this association strongly challenges FRB models thatinvoke young magnetars formed in a core-collapse su-pernova as powering FRB emission. We propose, in-stead, that FRB 20200120E is a highly magnetised neu-tron star formed via either accretion-induced collapseof a white dwarf or via merger of compact stars in a bi-nary system7. Alternative scenarios involving compactbinary systems, efficiently formed inside globular clus-ters, could also be responsible for the observed bursts.

2105.11445.pdf

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