Mysterious Blasts of Radiation Might Stem from Our Universe's Most Extreme Stars
For years, astronomers have been puzzled by the source of fast radio bursts (FRBs), enigmatic flashes of radiation that can be billions of times brighter than the Sun. These fleeting cosmic events, lasting just a few milliseconds, have been detected from billions of light-years away, suggesting they originate from outside our galaxy.
Now, a new study has provided compelling evidence that FRBs could be generated by some of the most extreme objects in the universe: neutron stars. These dense, ultra-compact remnants of massive stars are known for their powerful magnetic fields and energetic emissions.
The study, published in the journal Nature Astronomy, analyzed data from the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope, which has detected dozens of FRBs since it began operating in 2018. The researchers found that the polarization of FRBs, a property of light waves that indicates their alignment, matches the polarization of radio waves emitted by magnetars, a type of neutron star with exceptionally strong magnetic fields.
"This is a major breakthrough in our understanding of FRBs," said study co-author Shriharsh Tendulkar, a postdoctoral researcher at McGill University in Canada. "It provides strong evidence that magnetars are the sources of these enigmatic bursts."
Neutron stars are formed when massive stars collapse at the end of their lives. The tremendous gravitational forces at play squeeze the star's core into an incredibly dense object, about the size of a city but with the mass of the Sun. Neutron stars spin rapidly, generating powerful magnetic fields that can be billions of times stronger than Earth's.
Magnetars are a rare type of neutron star with magnetic fields that are even stronger, reaching up to a quadrillion times Earth's magnetic field. These intense magnetic fields can cause the star's surface to vibrate, generating bursts of radiation that can be detected across vast distances.
The new study suggests that FRBs are produced when magnetars undergo sudden changes in their magnetic fields, releasing a tremendous amount of energy in the process. This energy is then emitted in the form of a radio wave burst, which travels through the cosmos until it reaches Earth's telescopes.
"Our findings suggest that FRBs are not just single events," said Tendulkar. "They could be part of a larger evolutionary process in magnetars, where the star's magnetic field changes over time and releases bursts of energy."
The discovery of the link between FRBs and magnetars could have profound implications for our understanding of these extreme objects and the universe as a whole. It could also help astronomers identify the locations of FRBs more precisely, allowing them to study them in more detail and unravel the mysteries that surround them.