Chromatic periodic activity down to 120 megahertz in a fast radio burst

Abstract:

Fast radio bursts (FRBs) are extragalactic astrophysical transients whose brightness requires emitters that are highly energetic yet compact enough to produce the short, millisecond-duration bursts. FRBs have thus far been detected at frequencies from 8 gigahertz (ref. ) down to 300 megahertz (ref. ), but lower-frequency emission has remained elusive. Some FRBs repeat–, and one of the most frequently detected, FRB 20180916B, has a periodicity cycle of 16.35 days (ref. ). Using simultaneous radio data spanning a wide range of wavelengths (a factor of more than 10), here we show that FRB 20180916B emits down to 120 megahertz, and that its activity window is frequency dependent (that is, chromatic). The window is both narrower and earlier at higher frequencies. Binary wind interaction models pbkp_redict a wider window at higher frequencies, the opposite of our observations. Our full-cycle coverage shows that …

Año de publicación:

2021

Keywords:

Fuente:

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