A millisecond-duration radio burst from a galactic magnetar, dubbed SGR 1935+2154, has been detected using the Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope.
The finding of such a remarkably intense event could be significant for improving the understanding of the source of fast radio bursts (FRBs). Here are the latest details.
Magnetar SGR 1935+2154 Displays Odd Behavior
FRBs are known as intense bursts of radio emission lasting milliseconds that display characteristic distribution sweep of radio pulsars. The physical origin of these bursts is still unknown, and scientists have considered lots of explanations, including cosmic string cusps, and synchrotron maser discharge from young magnetars.
Magnetars are neutron stars with powerful magnetic fields, more than a quadrillion times greater than the magnetic field of Earth. The weakening of the magnetic field in magnetars fuels the discharge of high-energy electromagnetic radiation, for example, in the form of radio waves or X-rays.
The magnetar in question, SGR 1935+2154, is located approximately 30,000 light-years away in the Velcula constellation. It is known as a galactic magnetar that displays transient radio pulsations. It began a period of odd, intense X-ray burst activity, and a team of astronomers started to examine this pulsar with CHIME.
The results include the discovery of a two-component bright millisecond FRBs, similar to those observed at extragalactic lengths. There were also two sub-bursts detected of 0.585 and 0.355 milliseconds. The astronomers noted that such values, together with the estimated range to SGR 1935+2154, show 400-800MHz burst energy at a level of 30 decillion ergs – brighter than those of any radio-transmitting magnetar known so far.
The team is thinking now at the possibility that the recently detected burst could be an FRB. The morphology of the radio burst mirrors that of FRBs. The durations of its subcomponents are representative of the expanses of bursts from 18 repeating FRB sources found by CHIME.
The burst was discovered to be only one to two levels of magnitude below the tracked burst energies for typical FRBs. However, it could have comparable energies to some recognized FRBs if they were at their nearest possible extent.
Whether the newly discovered radio burst from SGR 1935+2154 is an FRB remains a big question. Still, the astronomers state that their detection might be useful in filling the energy gap between extragalactic FRBs and the most luminous galactic sources.
