Observations of neighboring pulsars did not help scientists find the source of mysterious antimatter flows that “bombard” the Earth from space, which indicates their extremely exotic origin.
“These measurements are interesting because they virtually completely exclude the possibility that these” extra “positrons reach the Earth from the two nearest pulsars, if we use the simplest models of their motion along the interstellar medium.” We do not say that they were accurately generated by dark matter, but now the new “pulsar” theories must somehow take into account what we found, “said Jordan Goodman of the University of Maryland (USA).
The story of this cosmic riddle began in 2008, when a Russian-Italian PAMELA antimatter detector, mounted on the Resurs-DK1 satellite, detected an unusually large number of high-energy positrons in near-Earth space. This was the first time that some cosmic object or process “fired” our planet with antimatter.
In 2013, these data were confirmed by the AMS-02 detector, installed on board the ISS in 2011, also found an unusual excess of antimatter in the Earth’s orbit. Antimatter, as was noted by scientists, was distributed around the near-Earth space in a rather random way, which for the first time indicated its possible exotic origin.
Goodman and his colleagues found unexpected evidence in favor of these ideas of Russian and Italian physicists, observing the cosmic rays of ultrahigh energies created in the atmosphere by the collision of terrestrial atoms with particles of antimatter, as well as with other types of cosmic rays, using the HAWC telescope.
The HAWC observatory is a set of three hundred vats with nearly two hundred tons of water, thoroughly purified from all impurities and radioactive substances, where you can observe the curious effect discovered by Soviet physicists almost a hundred years ago.
Back in 1934 Pavel Cherenkov and Sergey Vavilov noticed experimenting with gamma radiation that its entry into the liquid causes a weak but clearly noticeable glow in it because high-energy photons knock out electrons and accelerate them to velocities exceeding the speed of light in water. This effect has found wide application today, it is used to detect cosmic rays and to “catch” neutrinos.
Using HAWC, scientists tried to understand how many positrons produce two nearest pulsars – PSR B0656 + 14 and SN 437 in the constellation Gemini, considered today the main source of antimatter particles “bombarding” the Earth.
As scientists have suggested, if both these objects produce positrons, then those corners of the sky where they are located will be “highlighted” by beams of ultrahigh-energy gamma rays with a certain spectrum.
In either case, HAWC actually succeeded in detecting gamma radiation generated by the decay of antimatter, but its power was orders of magnitude lower than the values that both pulsars would have to produce if they served as the source of all antimatter reserves in the Earth’s orbit.
As scientists believe, the motion of positrons is prevented by clouds of gas and dust surrounding each pulsar and causing almost all antimatter particles to annihilate before they can reach the Earth.
It is possible that the source of this “extra” antimatter can really be dark matter, but, according to Goodman, while talking about this prematurely – you need to check all the other options before moving on to the most exotic explanation of this anomaly.