Events involving the mergers of neutron stars or the merger of a neutron star with a black hole, resulting in bursts of gravitational waves, have been found not to be linked to the sources of fast radio bursts. However, the complete dismissal of this theoretically predicted connection has not been confirmed and may be re-evaluated in the future. The findings were published in The Astrophysical Journal.
Fast radio bursts remain one of the primary enigmas in contemporary astrophysics. These bright, millisecond-duration radio pulses are observed at cosmological distances and can be either singular or repetitive. As of yet, there is no widely accepted theory explaining these phenomena, although in the case of repetitive fast radio bursts, there is increasing evidence of their connection to processes occurring within the magnetospheres of magnetars. However, it is unclear whether singular fast radio bursts possess a similar nature, or if their generation mechanisms are different.
A group of astronomers from the LIGO, Virgo, KAGRA, and CHIME/FRB collaborations, led by Richard Abbott from the California Institute of Technology, decided to test the hypothesis of the theoretically predicted link between fast radio bursts and events involving the mergers of binary neutron stars or the merger of a neutron star and a black hole, accompanied by gravitational wave bursts. Depending on the model, radio bursts can occur in the late stages of the merger, during the merger, or immediately after it.
The researchers analyzed observational data from the Advanced LIGO and Advanced Virgo gravitational observatories for the period of April to October 2019, as well as data from the ground-based CHIME radio telescope, which searches for fast radio bursts. The source of repetitive fast radio bursts, FRB 20200120E, discovered on January 20, 2020, was also separately studied. The analysis was conducted using two algorithms, with the first sample consisting of 22 singular fast radio bursts, and the second sample consisting of 29 singular and 11 repetitive fast radio bursts.
Scientists did not identify significant candidates among fast radio bursts for the role of sources of gravitational bursts. However, due to uncertainties in the distances to the targets, the possibility of such a connection is not entirely ruled out. The estimate for the number of fast radio bursts that could potentially be associated with events involving the mergers of neutron stars is no more than 15 percent, and for events involving the merger of a neutron star and a black hole, it is one percent. A similar follow-up study is possible in the future thanks to the increase in the volumes of data observations of these phenomena, as well as more accurate distance data to the sources of bursts.