Aces that first theorized in the 1970s are actions hypothetical particles proposed to preserve a time-reversal symmetry of nuclear power. These particles can form dark matter and can be thermally produced within the nucleus of neutron stars, escape from the stars due to their poor interaction with matter, and then change into X-rays in the magnetic fields surrounding the stars. In a paper in the journal Physical overview letters, astrophysicists point out that an excess of hard X-rays recently discovered from a nearby group of isolated neutron stars, known as the Magnificent Seven, can be explained by this emission mechanism.
The impression of an artist of a neutron star. Image Credit: Sci-News.com.
The Magnificent Seven is a group of isolated X-ray dim neutron stars at a distance of 400 to 2160 light-years from Earth.
These stars have powerful magnetic fields, and are only expected to produce low-energy X-rays and UV light.
“They are known to be very ‘boring’, and in this case it’s a good thing,” said Dr. Benjamin Safdi, a theoretical physicist from the U.S. Department of Energy, Lawrence Berkeley National Laboratory, said.
If actions exist, they will be expected to behave like neutrinos in a star, as both will have very small masses and are only very rarely and weakly related to each other. They could be produced in abundance inside stars.
Non-charged particles called neutrons move around inside neutron stars, sometimes alternating by scattering each other and releasing a neutrino or possibly an action. The neutrino-emitting process is the dominant way neutron stars cool down over time.
Like neutrinos, the actions could move outside the star. The incredibly strong magnetic field around the Magnificent Seven stars can cause retiring actions to convert into light.
“The action was first proposed in the late 1970s to solve a problem called the strong CP problem, which means that the negative and positive distribution of electric charge within the neutron is centered around the same point,” he said. Christopher Dessert, a graduate student at the University, said. of Michigan.
“In the next decade, it was discovered that if the action existed, it could also be dark matter.”
In 2019, astrophysicists observed a mysterious, unexplained increase in X-rays appearing from the Magnificent Seven.
Dr. Safdi, Dessert and their colleagues suggest that these extra X-rays are caused by actions produced in the nuclei of the neutron stars.
If the excess of the X-ray is generated by an object or objects hidden behind the neutron stars, it would probably have shown in the data sets used by the researchers of two space satellites: XMM-Newton from ESA and Chandra X-ray telescopes from NASA. .
‘It is still quite possible that a new, non-action statement will emerge to take into account the observed X-ray excess, although we remain hopeful that such a statement goes beyond the standard model of particle physics and the new ground and space will lie. experiments will confirm the origin of the high-energy X-ray signal, ”said Dr Safdi.
“We are fairly confident that this co-payment exists, and very confident that there is something new among this excess.”
‘If we were 100% sure that what we were seeing was a new particle, it would be big. It would be revolutionary in physics. ”
‘Even though it seems that the discovery is not related to a new particle or dark matter. It would tell us so much more about our Universe, and there would be much to learn. ”
“We do not yet claim that we discovered the action, but we do say that the extra X-rays can be explained by actions,” said Dr. Raymond Co., a postdoctoral researcher at the University of, said. Minnesota.
“It’s an exciting discovery of the excess in the X – rays, and it’s an exciting possibility that already matches our interpretation of actions.”
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Malte Buschmann et al. 2021. Axion emission may explain a new hard X-ray excess of nearby isolated neutron stars. Fis. Ds Lett 126 (2): 021102; doi: 10.1103 / PhysRevLett.126.021102