NASA’s NICER sees extremely hot spots on the surface of a magnetar

A magnetar is an unique neutron star with an ultra-powerful magnetic subject. It's 1,000 instances stronger than a standard neutron star.

On Oct. 10, 2020, NASA’s Neil Gehrels Swift Observatory found simply such an outburst from a brand new magnetar, known as SGR 1830-0645.

NASA‘s Neutron star Inside Composition Explorer (NICER) tracked how three brilliant, X-ray-emitting sizzling spots slowly wandered throughout the magnetar’s floor. In different phrases, it noticed the merging of multimillion-degree X-ray spots on the magnetar’s floor.

On the similar time, these spots have been discovered to lower in dimension. The biggest spot finally merged with a smaller one, which we hadn’t seen earlier than.

These three shifting sizzling spots seemingly signify the place coronal loops hook up with the floor. The interplay between these loops and crustal movement drives the drifting and merging conduct.

George Younes, a researcher at George Washington College in Washington and NASA’s Goddard House Flight Middle in Greenbelt, Maryland, mentioned, “This distinctive set of observations will assist information scientists to a whole understanding of the interaction between the crust and magnetic subject of those excessive objects.”

This plot tracks 37 days of change in SGR 1830’s peak X-ray emission as seen by NASA’s Neutron star Inside Composition Explorer (NICER). On this graph, the star’s rotational section advances from left to proper, with the measured vitality proven vertically. The inexperienced, yellow, and pink areas point out areas producing the best numbers of X-rays and are thought to signify the magnetar’s sizzling spots. They modify in depth and of their positions relative to every one other as time goes on. For the primary time, astronomers recorded two such spots merging.
Credit score: NASA/NICER/G. Younes et al. 2022

The measurements additionally demonstrated that the X-ray emission exhibited three shut peaks with each rotation. They have been brought on when three particular person floor areas spun into and out of our view a lot hotter than their environment.

Sam Lander, an astrophysicist on the College of East Anglia in Norwich, United Kingdom, mentioned, “The crust of a neutron star is immensely robust, however a magnetar’s intense magnetic subject can pressure it past its limits. Understanding this course of is a significant problem for theorists, and now NICER, and SGR 1830 have introduced us a way more direct have a look at how the crust behaves beneath excessive stress.”

Zaven Arzoumanian, the NICER science lead at Goddard, mentioned, “Modifications in pulse form, together with lowering numbers of peaks, beforehand have been seen solely in a couple of ‘snapshot’ observations extensively separated in time, so there was no solution to monitor their evolution. Such adjustments might have occurred all of the sudden, which might be extra in line with a lurching magnetic subject than wandering sizzling spots.”