Astronomers Detect Short Bursts of Radio Waves from Distant Magnetar

Using ESA’s International Gamma-Ray Astrophysics Laboratory (Integral), NASA’s Neil Gehrels Swift Observatory and several radio telescopes, astronomers have detected short and very bright radio bursts as well as gamma- and X-rays from SGR 1935+2154, a magnetar located 4,400 parsecs (14,351 light-years) away in the constellation of Vulpecula.

An artist’s impression of the magnetar SGR 1935+2154. Image credit: ESA.

Discovered in 2014 following a substantial burst of X-rays, SGR 1935+2154 became active again in April 2020.

The Integral space observatory detected a burst of X-rays on April 28, 2020, automatically alerting observatories worldwide about the discovery.

“We detected the magnetar’s burst of high-energy X-rays using Integral on April 28,” said lead author Dr. Sandro Mereghetti, a researcher at Italy’s National Institute for Astrophysics (INAF-IASF).

“Integral’s ‘Burst Alert System’ automatically alerted observatories worldwide about the discovery in just seconds.”

“This was hours before any other alerts were issued, enabling the scientific community to act fast and explore this source in more detail.”

The CHIME radio telescope spotted a short and extremely bright burst of radio waves from the direction of SGR 1935+2154 on the same day, over the same timeframe as the X-ray emission.

This was independently confirmed a few hours later by the Survey for Transient Astronomical Radio Emission 2 (STARE2).

“We’ve never seen a burst of radio waves, resembling a fast radio burst, from a magnetar before,” Dr. Mereghetti said.

“Crucially, the Imager on-board Integral (IBIS) instrument allowed us to precisely pinpoint the origin of the burst, nailing its association with the magnetar,” said Dr. Volodymyr Savchenko, an astronomer in the Integral Science Data Centre at the University of Geneva.

“Most of the other satellites involved in the collaborative study of this event weren’t able to measure its position in the sky — and this was crucial in identifying that the emission did indeed come from SGR1935+2154.”

“This is the first ever observational connection between magnetars and fast radio bursts,” Dr. Mereghetti said.

“It truly is a major discovery, and helps to bring the origin of these mysterious phenomena into focus.”

This connection strongly supports the idea that fast radio bursts emanate from magnetars, and demonstrates that bursts from these highly magnetized objects can also be spotted at radio wavelengths.

“By bringing together observations from the high-energy part of the spectrum all the way to radio waves, from across the globe and in space, we have been able to elucidate a long-standing mystery in astronomy. We’re thrilled that Integral played a key role in this,” said Integral project scientist Dr. Erik Kuulkers, a researcher at ESA.

The team’s paper was published in the Astrophysical Journal Letters.