Astronomers have been tirelessly studying fast radio bursts (FRBs) for over 15 years in an attempt to unravel their mysterious origins and formation. FRBs are brief but intense cosmic explosions of electromagnetic radiation that predominantly originate from beyond our own Milky Way galaxy.
However, in a groundbreaking discovery, scientists have found that the first Galactic FRB, known as FRB 20200428, actually emanated from a magnetar known as SGR J1935+2154, which is a dense neutron star with a remarkably powerful magnetic field. This groundbreaking revelation has raised the possibility that magnetars could be responsible for cosmological FRBs as well.
Despite this revelation, there has been no detection of the rotation period caused by the magnetar’s spin, which would serve as evidence supporting this hypothesis. But now, new research on SGR J1935+2154 has shed some light on this discrepancy.
In a recent study published in Science Advances, astronomers discuss their continued monitoring of SGR J1935+2154 following the April 2020 FRB, leading to the discovery of a radio pulsar phase. To observe these bursts and the pulsar phase, scientists utilized the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China.
Interestingly, researchers found that the FRB and the subsequent pulsar phase actually originated from different regions within the magnetar, indicating different origins. This observation provides essential insights into the occurrence of FRBs within our galaxy and potentially at cosmological distances.
It is important to note that FRBs differ from radio pulses emitted by pulsars in terms of their emission modes and phases. The pulsar phase emitted from SGR J1935+2154 occurs within a narrow window, whereas the FRB bursts are emitted in random phases. This discrepancy suggests that pulses and bursts have distinct emission mechanisms and originate from separate locations within the magnetar magnetosphere.
The implications of this study are significant, particularly for understanding cosmological FRBs, especially those that repeat. The lack of periodicity detected in repeating FRBs raises doubts about the theory that they are powered by magnetars. Due to the random emission of bursts in all directions, it is simply impossible to identify any discernible periods from FRB sources.
With further research and observations, astronomers hope to continue unraveling the mysteries surrounding these enigmatic FRBs. The findings from this study represent a crucial step forward in our understanding of these cosmic phenomena and may potentially pave the way for future breakthroughs in this fascinating field of study.
