April 14, 2024


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NASA’s NICER telescope sees hot spots merge on a magnetar — ScienceDaily

For the initially time, NASA’s Neutron star Interior Composition Explorer (NICER) has observed the merging of multimillion-degree X-ray spots on the surface area of a magnetar, a supermagnetized stellar core no much larger than a metropolis.

“NICER tracked how three vivid, X-ray-emitting sizzling spots slowly but surely wandered across the object’s surface area though also reducing in dimension, furnishing the greatest glance still at this phenomenon,” reported George Younes, a researcher at George Washington University in Washington and NASA’s Goddard Room Flight Middle in Greenbelt, Maryland. “The greatest place eventually coalesced with a smaller sized one, which is a little something we haven’t viewed prior to.”

This distinctive set of observations, explained in a paper led by Younes and printed Jan. 13 in The Astrophysical Journal Letters, will aid guideline researchers to a far more complete knowing of the interaction in between the crust and magnetic area of these serious objects.

A magnetar is a kind of isolated neutron star, the crushed core remaining guiding when a large star explodes. Compressing much more mass than the Sun’s into a ball about 12 miles (20 kilometers) across, a neutron star is produced of matter so dense that a teaspoonful would weigh as a great deal as a mountain on Earth.

What sets magnetars aside is that they sport the strongest magnetic fields known, up to 10 trillion situations additional intense than a refrigerator magnet’s and a thousand times stronger than a common neutron star’s. The magnetic subject represents an massive storehouse of electrical power that, when disturbed, can energy an outburst of improved X-ray exercise long lasting from months to many years.

On Oct. 10, 2020, NASA’s Neil Gehrels Swift Observatory identified just such an outburst from a new magnetar, known as SGR 1830-0645 (SGR 1830 for limited). It can be located in the constellation Scutum, and while its distance is not specifically acknowledged, astronomers estimate that the object lies about 13,000 gentle-yrs away. Swift turned its X-Ray Telescope to the source, detecting recurring pulses that unveiled the object was rotating each 10.4 seconds.

NICER measurements from the same working day clearly show that the X-ray emission exhibited a few close peaks with every single rotation. They were being triggered when 3 person surface areas a lot hotter than their environment spun into and out of our look at.

NICER noticed SGR 1830 practically day-to-day from its discovery to Nov. 17, immediately after which the Solar was as well shut to the subject of see for safe observation. Over this interval, the emission peaks step by step shifted, transpiring at a little bit distinctive moments in the magnetar’s rotation. The final results favor a model exactly where the spots form and shift as a result of crustal movement, in considerably the identical way as the movement of tectonic plates on Earth drives seismic exercise.

“The crust of a neutron star is immensely powerful, but a magnetar’s extreme magnetic subject can strain it over and above its restrictions,” mentioned Sam Lander, an astrophysicist at the University of East Anglia in Norwich, United Kingdom, and a co-creator of the paper. “Being familiar with this procedure is a important obstacle for theorists, and now NICER and SGR 1830 have introduced us a a great deal far more immediate look at how the crust behaves underneath severe tension.”

The staff thinks these observations expose a single lively location where by the crust has grow to be partially molten, gradually deforming underneath magnetic worry. The 3 moving sizzling spots most likely symbolize areas the place coronal loops — identical to the brilliant, glowing arcs of plasma observed on the Sun — join to the area. The interplay amongst the loops and crustal motion drives the drifting and merging behavior.

“Improvements in pulse condition, together with reducing quantities of peaks, formerly have been found only in a few ‘snapshot’ observations broadly separated in time, so there was no way to track their evolution,” said Zaven Arzoumanian, the NICER science direct at Goddard. “These kinds of changes could have happened all of a sudden, which would be far more steady with a lurching magnetic industry than wandering scorching spots.”

NICER is an Astrophysics Mission of Possibility in NASA’s Explorers Plan, which offers regular flight opportunities for environment-class scientific investigations from place employing ground breaking, streamlined, and productive management approaches within the heliophysics and astrophysics science locations. NASA’s Room Technological know-how Mission Directorate supports the SEXTANT element of the mission, demonstrating pulsar-centered spacecraft navigation.