Multimillion-degree hot spots merging on a Magnetar have been discovered by an international team including a researcher at the University of East Anglia.
A Magnetar is a supermagnetized stellar core no larger than a city. It is a type of isolated neutron star, the crushed core left behind when a massive star explodes.
Compressing more mass than the Sun’s into a ball about 12 miles across, a neutron star is made of matter so dense that a teaspoonful would weigh as much as a mountain on Earth.
What sets magnetars apart is that they sport the strongest magnetic fields known, up to 10 trillion times more intense than a refrigerator magnet’s and a thousand times stronger than a typical neutron star’s.
The magnetic field represents an enormous storehouse of energy that, when disturbed, can power an outburst of enhanced X-ray activity lasting from months to years.
It is hoped that the discovery will help guide scientists to a more complete understanding of the interplay between the crust and magnetic field of these extreme objects.
The discovery was made using NASA’s Neutron star Interior Composition Explorer (NICER) telescope, and UEA’s Dr Sam Lander has been part of the international team, playing a major role in the theoretical interpretation of the observations.
Dr Lander, an astrophysicist from UEA’s School of Physics, said: “Magnetars are a kind of ultra-dense star powered by a strong magnetic field. Studying them combines many different aspects of physics - which means that those of us working in this research field are always kept busy, especially since new observations habitually throw up more surprises.
“Magnetars have a solid crust that sometimes breaks - parts of it are moved out of place, like an earthquake - and one major strand of my own research has been understanding how this process works.
“Here at UEA I have been particularly focussed in following this crustal motion through computer simulations and comparing my theoretical results with observations.
“This paper reports a completely new phenomenon from a magnetar - the observation of hot spots drifting across its surface.
“My co-authors and I believe that this hotspot drifting is the most direct evidence to date of crustal failure, and so gives me really valuable information to incorporate into my own models.
“Together with a wealth of other recent observations, it is a really exciting time to be working on magnetar physics,” he added.
‘Pulse Peak Migration during the Outburst Decay of the Magnetar SGR 1830-0645: Crustal Motion and Magnetospheric Untwisting’ is published in the journal Astrophysical Journal Letters: https://iopscience.iop.org/article/10.3847/2041-8213/ac4700