Magnetar, a super-dense object in the galaxy, has been linked to mysterious radio bursts astronomers have been detecting since 2007.
The link of Magnetar to these radio bursts has prompted a series of new questions. Since 2007, hundreds of Fast Radio Bursts (FRBs), which are millisecond-long pulses, were found throughout the galaxy. However, astronomers have become excited by the discovery of FRBs inside the Milky Way in April this year.
This burst has been called FRB 200428, and it appears to have originated in magnetar SGR 1935+2154, a highly magnetic neutron star. Scientists are now speculating that the FRBs may have been terminating from the magnetar after collecting, inspecting, cross-referencing and correcting all data available to the independent scientists.
Astrophysicists at the University of Cape Town, Amanda Weltman and Anthony Walters, wrote in a News and Views article that there actually is no observational evidence that conclusively links the magnetars with FRBs. According to scientists, the first evidence of these FRBs were reported in the three new papers, providing vital new clues that are integral to the understanding of FRB origins.
It is possible that the connection has been made due to international cooperation, where multiples observatories collected and shared their data from both space and the ground. The information that was collated, and evidence that the FRBs were found alongside gamma rays and X-rays, was significant in the search for clues about this celestial phenomenon.
At first, the pulses were thought to be on–off emissions, however, scientists found some repetition, leading to the assumption that some FRBs were not produced by a catastrophic event.
Neutron stars, supernova explosions and unknown interactions with black holes were among the theories sources of the FRBs. The previous idea that FRBs exclusively came from outside our galaxy demonstrates the importance on FRB 200428.
“So far, all of the FRBs that telescopes…have picked up were in other galaxies, which makes them quite hard to study in great detail.”
PhD student at McGill University in Montreal, Ziggy Pleunis, alongside a co-author, explains the viewing of FRBs in a study by the Canadian Hydrogen Intensity Mapping Experiment.
The Neil Gehrels Swift Observatory and the Fermi Gamma-ray Space Telescope, two space telescopes, found these bursts on April 27, in X–rays and gamma rays. The bursts were detected in the direction of magnetar SGR 1935+2154.
However, it wasn’t until the next day that CHIME astronomers detected the bright radio pulses that caused excitement. On this same day, STARE2 scientists (Survey for Transient Astronomical Radio Emission 2) detected the same thing from the US southwest.
STARE2 astrophysicist Christopher Bochenek explains the way he, and his colleagues, were “paralysed with excitement” over the discovery they had made in April. He explains that the burst was so strong even a mobile phone could have detected it if it had been tuned into the right frequency at the right time.
“This is the first FRB that comes from a known object.”
A California Institue of Technology researcher asserted that the radio burst detected was equal to that which the sun produces every 30 seconds.
ESA’s INTEGRAL space telescope, Russia’s Konus instrument and China’s Insight space telescope all found X-ray signals during the burst from the magnetar. This means that five separate observatories around the world captured the same event in some form.
As explained by Weltman and Walters, the FRB 200428 is the first time more than just radio waves were detected in the emissions. On top of this, it is the first of its kind to be detected within in Milkey Way and the first to be associated with a magnetar. They further explain that the burst was the brightest ever measured from a Galactic magnetar. It is more exciting that this is the first radio burst from FRB 200428, which provides scientists with evidence that could link magnetars to extragalactic FRBs.
There is unfortunately not a lot of information about FRBs due to limitations on data, problems with observational selection effects and the intense distances that are involved with space research. Despite this, the association of a galactic FRB that was found within our galaxy with a magnetar is a huge step for scientists.
This gives hope that we can build on the extensive research put into FRBs build over the past 13 years and continue to learn more in upcoming years.