April 25, 2024

Revealing the Secrets of Magnetars – Researchers Test “Anti-Glitch” Theory

The research study recognized how such a wind might modify the stars magnetic fields, seeding conditions that would be likely to change on the radio emissions that were consequently measured by Chinas Five-hundred-meter Aperture Spherical Telescope (FAST).
Matthew Baring is a professor of physics and astronomy at Rice University. Credit: Henry Baring
” People have actually speculated that neutron stars might have the equivalent of volcanoes on their surface,” said Baring, a professor of physics and astronomy. “Our findings suggest that could be the case which on this occasion, the rupture was more than likely at or near the stars magnetic pole.”
SGR 1935 +2154 and other magnetars are a type of neutron star, the compact remains of a dead star that collapsed under extreme gravity. About a dozen miles large and as dense as the nucleus of an atom, magnetars rotate once every few seconds and feature the most extreme magnetic fields in deep space.
Magnetars give off intense radiation, consisting of X-rays and periodic radio waves and gamma rays. Astronomers can understand much about the unusual stars from those emissions. By counting pulses of X-rays, for instance, physicists can compute a magnetars rotational period, or the quantity of time it takes to make one total rotation, as the Earth performs in one day. The rotational durations of magnetars generally change gradually, taking 10s of countless years to slow by a single rotation per second.
Glitches are abrupt increases in rotational speed that are most often triggered by abrupt shifts deep within the star, Baring said.
” In a lot of problems, the pulsation period gets much shorter, indicating the star spins a bit much faster than it had actually been,” he stated. “The textbook description is that over time, the outer, magnetized layers of the star slow down, but the inner, non-magnetized core does not. This causes an accumulation of stress at the limit in between these two areas, and a problem indicates an unexpected transfer of rotational energy from the much faster spinning core to the slower spinning crust.”
Abrupt rotational slowdowns of magnetars are very unusual. Astronomers have only taped 3 of the “anti-glitches,” including the October 2020 event.
While glitches can be routinely explained by modifications inside the star, anti-glitches likely can not. Barings theory is based upon the assumption that they are caused by modifications on the surface of the star and in the area around it. In the new paper, he and his co-authors built a volcano-driven wind model to explain the determined arise from the October 2020 anti-glitch.
Baring said the model utilizes just basic physics, particularly modifications in angular momentum and preservation of energy, to represent the rotational downturn.
” A strong, massive particle wind originating from the star for a few hours could establish the conditions for the drop in rotational period,” he stated. “Our estimations revealed such a wind would likewise have the power to alter the geometry of the magnetic field outside the neutron star.”
The rupture could be a volcano-like formation, because “the general homes of the X-ray pulsation most likely require the wind to be introduced from a localized area on the surface,” he said.
” What makes the October 2020 occasion special is that there was a quick radio burst from the magnetar just a couple of days after the anti-glitch, along with a switch-on of pulsed, ephemeral radio emission shortly thereafter,” he stated. “Weve seen just a handful of transient pulsed radio magnetars, and this is the first time weve seen a radio switch-on of a magnetar nearly simultaneous with an anti-glitch.”
Baring argued this timing coincidence recommends the anti-glitch and radio emissions were caused by the exact same event, and hes enthusiastic that additional studies of the volcanism design will supply more responses.
” The wind analysis provides a path to comprehending why the radio emission turns on,” he stated. “It provides new insight we have actually not had prior to.”
Referral: “Magnetar spin-down problem clearing the method for FRB-like bursts and a pulsed radio episode” by G. Younes, M. G. Baring, A. K. Harding, T. Enoto, Z. Wadiasingh, A. B. Pearlman, W. C. G. Ho, S. Guillot, Z. Arzoumanian, A. Borghese, K. Gendreau, E. Göğüş, T. Güver, A. J. van der Horst, C.-P. Hu, G. K. Jaisawal, C. Kouveliotou, L. Lin and W. A. Majid, 12 January 2023, Nature Astronomy.DOI: 10.1038/ s41550-022-01865-y.
The study was moneyed by the National Science Foundation, Japans RIKEN Advanced Science Institute, and Taiwans Ministry of Science and Technology.

On October 5th, 2020, a rapidly rotating residue of a long-dead star situated around 30,000 light-years away from our planet experienced an unexpected modification in speed. Astronomers can understand much about the unusual stars from those emissions.” In the majority of glitches, the pulsation duration gets shorter, suggesting the star spins a bit quicker than it had actually been,” he stated. While problems can be consistently explained by changes inside the star, anti-glitches most likely can not. Barings theory is based on the presumption that they are triggered by modifications on the surface area of the star and in the area around it.

An artists impression of a magnetar eruption. Credit: NASAs Goddard Space Flight Center
The sudden slowdown of a star in 2020 offers an opportunity to check the “anti-glitch” theory.
On October 5th, 2020, a quickly rotating remnant of a long-dead star situated approximately 30,000 light-years far from our world experienced a sudden modification in speed. In a cosmic instant, its spinning slowed. And a few days later, it abruptly began releasing radio waves.
Rice University astrophysicist Matthew Baring and his team had the ability to test a brand-new theory about the cause of the unusual slowdown, or “anti-glitch,” of SGR 1935 +2154, an extremely magnetic neutron star described as a magnetar, due to prompt measurements from specialized orbiting telescopes.
In a research study published this month in Nature Astronomy, Baring and co-authors used X-ray information from the European Space Agencys X-ray Multi-Mirror Mission (XMM-Newton) and NASAs Neutron Star Interior Composition Explorer (NICER) to examine the magnetars rotation. They showed the abrupt downturn might have been brought on by a volcano-like rupture on the surface area of the star that spewed a “wind” of massive particles into area.