New research has shown that different types of neutron stars, born when massive stars die, behave in a similar way. This may sound like a small result, but in the big picture it’s a finding that further supports the idea that these extremely dead stars – so dense that a tablespoon of one is equal to something like the weight of Mount Everest – are behind mysterious explosions could sit. of radiation called Fast Radio Bursts (FRBs).
Millisecond-long bursts of radio emission FRBs appear to come from sources beyond the boundaries of the Milky WayBut since their discovery in 2007, their origins have remained shrouded in mystery. However, there is one possible suspect: highly magnetic neutron stars, or magnetars.
And the team behind the new discovery, including researchers from the Max Planck Institute for Radio Astronomy (MPIfR) and the University of Manchester, found that magnetars do indeed share a relationship between pulse structure and rotation that is also present in other so-called ‘radio astronomy’ . -loud” neutron stars.
The discovery of a similar ‘universal scale’ between different types of neutron stars hints at the plasma processes that may be responsible for these radio emissions themselves; it also leads scientists to interpret structures in FRBs as the result of a corresponding period of rotation, the team says.
“When we started comparing magnetar emissions to those from FRBs, we expected similarities,” said Michael Kramer, first author of a paper on the findings and director of MPIfR, said in a statement. ‘What we didn’t expect is that all radio-loud neutron stars share this universal scale.
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Neutron stars! Pulsars! Magnetars! Oh my!
Neutron stars form when they are massive stars run out of fuel nuclear fusion. Once a star runs out of fuel, the energy that sustains it will go against the inner, crushing force of its own power. gravity ceases to exist. This then causes the star’s outer layers to be blown away, resulting in mass supernova explosions as the core itself collapses.
That collapse continues until electrons And protons in the region collide with each other and create a sea of neutron-rich matter, which prevents the star’s core from being crushed even further. Any more and the core would eventually become one black hole. However, without a black hole, the result of the core collapse process is a body the width of a city here Soil – about 20 kilometers – and matter that is incomprehensibly dense. Consider the example of Mount Everest.
However, this is not the only extreme quality that causes the gravitational collapse. Just as an ice skater can speed up his rotation by retracting his arms, the stellar cores that create neutron stars become smaller in radius and therefore “spin up.” This spin-up process can significantly influence a core. For example, some younger neutron stars can spin as much as 700 times per second. And as they emit beams of radiation that sweep across the Earth, like a beam from a cosmic lighthouse, the rapidly spinning neutron star is called a pulsar. Neutron stars that rotate hundreds of times per second are called millisecond pulsars.
although pulsars are notable for their periodic nature. ‘Rotating Radio Transients’, on the other hand, are neutron stars that emit more sporadic and less well-timed bursts of radio waves.
Furthermore, when the magnetic field lines of stellar cores “collapse” during this collapse, magnetic fields are created that a thousand billionN times stronger than the Earth’s magnetic field are created. But some neutron stars have more powerful magnetic fields than even that, pushing boundaries a thousand times stronger than those of a ‘normal’ neutron star.
These are known as magnetars.
Astronomers know of about thirty magnetars so far, and about six of them have been observed to emit radio waves. Scientists assume that FRBs come from magnetars outside the Milky Way: extragalactic magnetars.
Finding a connection between all ‘radio-loud’ neutron stars
The team began investigating the possible link between magnetar and FRB by examining in detail the individual pulses of the six known magnetars. They then examined the substructure of the pulses with the Effelsberg Radio Telescope in Bad Münstereifel, Germany, one of the largest fully directional radio telescopes on Earth.
To the team’s surprise, the rapidly rotating millisecond pulsars and Rotating Radio Transients have similar pulse structures. This led them to a universal scaling relationship for magnetars and the other forms of neutron stars that connects the pulse structure to the rotation period, whether these extreme stars rotate every few milliseconds or in about 100 seconds.
“We expect magnetars to be powered by magnetic field energy, while the others are powered by their rotational energy,” Kuo Liu, team member and scientist at MPIfR, said in the statement. “Some are very old, some are very young, and yet they all seem to follow this law.”
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In other words, the fact that all these radio-wave-emitting neutron stars behave like magnetars suggests that the intrinsic origin of the subpulse structure must be the same for all radio-wave-emitting neutron stars.
“If at least some FRBs come from magnetars, the time scale of the substructure in the outburst could then tell us the rotation period of the underlying magnetar source,” Ben Sappers, team member and researcher at the Jodrell Bank Center for Astrophysics, said in the statement. “If we find this periodicity in the data, it would be a milestone in explaining this type of FRB as radio sources.”
The team’s research was published in the journal on November 23 Nature Astronomy.