Astronomers have discovered an unusual fast radio burst in a quiet neighboring galaxy, raising new questions about the occurrence of this phenomenon. The new discovery, published in The Astrophysical Journal, suggests that fast radio bursts occur not only in turbulent environments, but also in colliding galaxies, where conditions favor the formation of massive progenitor stars.
FRB 20211127I was detected using the Square Kilometer Array Pathfinder CSIRO radio telescope in the parent galaxy WALLABY J131913-185018. This galaxy is characterized by the emission of neutral hydrogen, whose mass is estimated at 6.5 billion solar masses. However, the hallmark of the galaxy is its quiescent state, which raises doubts that massive stars could arise in some other way, or the source of the outburst is an entirely different object.
Previously, it was thought that the most likely source of FRBs were neutron stars belonging to magnetars. However, these compact objects with an extreme magnetic field arise from the explosion of massive stars that form in turbulent environments. Scientists believe that the progenitor star could have arisen in a region of excess stellar density in a galaxy arm or even due to an unobserved tidal interaction.
Galaxies with FRB are characterized by strongly asymmetric HI spectra or strongly perturbed hydrogen atomic distributions. This occurs in tidal interactions between merging galaxies, resulting in star formation outbursts. Although some asymmetry is present in W13-18, astronomers note that there is great uncertainty in the data on atomic hydrogen in this galaxy. In optical light, the galaxy shows no signs of perturbation.
The discovery has raised new questions about the origin of FRB. The detection of a radio burst in a quiescent galaxy, where there are no conditions for the formation of massive progenitor stars, calls into question previous hypotheses about the origin of this phenomenon. Scientists continue to investigate the data to understand how fast radio bursts arise.
