A small pulsar frees a gigantic particle beam: a clue to the origin of antimatter


You may also like this partner content (after ad)

Antimatter, this sort of opposite of baryonic matter (the ordinary matter that surrounds us), exists only in minute quantities in the universe. If we know that it can be issued from releases of cosmic objects releasing very large quantities of energy (such as the explosion of a supernova or the energy beam of a pulsar), it is often more sequestered by the powerful magnetic fields emanating from these objects. A new observation from NASA’s Chandra Space Telescope has transmitted the image of a small pulsar from barely 16 km in diameter projecting a gigantic beam of matter and antimatter. Length of 16 billion kilometers, this is the largest pulsar beam ever observed from Earth. This extraordinary power for such a small cosmic object has generated an unexpected phenomenon which could perhaps explain the origin of antimatter in the universe.

Pulsars (or neutron webs) are most often born from the collapse of the highly dense core of a massive web, which explodes into a supernova at the end of its life. They are characterized by their high speed of rotation and the emission of a periodic electromagnetic beam sweeping space (due to the rapid rotation of the star on itself).

Baptized PSR J2030+4415, the pulsar photographed by Chandra was identified at 2020, but as it was located beyond the limit ( 600 light-years from Earth) of the detector that the space observatory was using at the time, scientists had not yet been able to take the full measurement of its electromagnetic beam.

Thanks to a new observation in X-rays, researchers from NASA and Stanford University have discovered that this beam was actually three times larger than their original estimate. Even for a pulsar of this diameter, the rotation frequency is impressive (three revolutions per second). The electromagnetic ray extends over 16 000 billion km (about half the diameter of the moon seen from Earth)! To get a better idea of ​​this, imagine a sphere the size of a small town spinning faster than a standard ceiling fan

It’s incredible that a pulsar of only miles (16 km) in diameter could create a structure so large that we can see it from thousands of light-years , enthuses in a press release Martijn de Vries, researcher at Stanford University and main author of the study. To compare, with the same relative size, if the filament extended from New York to Los Angeles, the pulsar would be approximately 600 times smaller than the smallest visible lil naked object, explain- he in the press release. The details of the study will be published shortly in The Astrophysical Journal and are already available on the server arXiv.

Although the vast majority of the universe is made up of ordinary matter and primordial antimatter (which coexisted in equal mass with primordial matter at the time of the Big Bang according to our theories) has almost completely disappeared, a number large number of positrons (antiparticle of the electron) continues to be detected from Earth. The results of this new study may provide new clues as to the possible source of antimatter present in the Milky Way.

A new kind of pulsar that lets antimatter escape

What you need to know is that the electromagnetic beams emanating from pulsars contain matter and antimatter. Antimatter has basically the same mass as ordinary matter, but with opposite electrical charges. It is composed of antiparticles, counterparts of particles in ordinary matter. In the radiance of PSR J2030+4415, researchers have detected positrons, the positively charged equivalents of electrons. as well as high-speed rotation, two extreme conditions that pulsars can generate. These parameters lead to particle acceleration and high energy radiation. Which can create electron and positron pairs. The usual process of converting mass into energy (according to Albert Einstein’s equation E = mc) is thus reversed, because energy is converted into mass.

However , it was previously believed that the magnetic fields of pulsars did not let any positrons escape. And yet, this new pulsar could apparently have let some escape into space. As it moves near 1 600 000 km/h according to estimates, it creates winds loaded with particles. These particles are generally believed to be confined within the strong magnetic fields of the pulsar. generally in front of the pulsars, similar to the accumulation of water created by the prow of a boat, splits the water while advancing which. However, there are approximately 16 30 years, this movement seems to have stopped for PSR J2030 + 600, and the latter catches up with her. This resulted in an interaction with the interstellar magnetic field, which itself acts almost in a straight line and from left to right. This latter mechanism could then have caused a particle leak. The magnetic field of the pulsar’s wind bonded with the interstellar magnetic field, and the high-energy electrons and positrons escaped through a channel formed by connection , says Roger Romani, co-author of the study and also a researcher at Stanford University.

According to the authors of the study, the powerful and long beam emanating from PSR J2030+4415 demonstrates that charged particles can disperse in space, and potentially reach the Earth, which could perhaps explain the high rate of positrons detected in the Milky Way.

Source: arXiv