Availability magnetic fields in space this has been more than demonstrated. In fact, this has a lot to do with the auroras that we have recently been able to enjoy in places very far from what we are used to. However, the origin and evolution of these magnetic fields have long remained a mystery. Fortunately, there are more and more answers, such as the one that two Chinese scientists just gave about magnetic fields of the Milky Way.
One of them, Professor Khanis in the path of these magnetic fields since 1997. That year he discovered something interesting: “antisymmetry of Faraday effects cosmic radio sources in the sky relative to the coordinates of this galaxy.” Now we will see what all these terms mean. To him at the time, this demonstrated that the magnetic fields in the Milky Way halo had a toroidal field structure because their directions were inverted below and above the galactic plane.
The problem is that he couldn’t figure out the size of these toroids nor the strength of its magnetic fields. Thus, the mystery of cosmic magnetic fields had many pieces to put together. Now, thanks to advances in observation technology, Han and his colleague Professor Xu have been able to place several more fragments.
Key concepts needed to understand the parts you just placed
The Faraday effect refers to the deflection of the plane of polarization of light when passing through a transparent material exposed to an intense magnetic field. Therefore, at one time Khan relied on analysis Faraday effect of the Milky Way to better study its magnetic field. By analyzing how polarized light bends, we were able to understand what was happening.
The deviations he discovered could only be explained by a toroidal magnetic field, since disk. It looks much better in the picture below.
Once this discovery was made, he needed to know how far this magnetic field extended and what its intensity was. It took many more years to give the answer, but he finally got it thanks to some very valuable stars in the study of magnetism: pulsars.
Pulsars for analyzing magnetic fields in our galaxy
Pulsars rapidly rotating neutron stars and are highly magnetized. They have many functions in astronomy. For example, they were used to map space because their brightness decreases with the square of the distance from a certain point. In addition, they emit polarized light, so they can help in calculating the Faraday effect.
These Chinese scientists wanted to test whether magnetic fields outside the Sun have the structure of a torus. And for this, the best option was to get as much data as possible from pulsars.
Professor Xu collected all the Faraday rotation measurements over the past 30 years. Thus, the two colleagues were able to verify that a phenomenon detected in the galaxy’s halo, known as antisymmetry, exists throughout the sky, from the center to the anticenter of our Milky Way. This means that “toroidal magnetic fields of such strange symmetry are of enormous size and exist in the range of radii from 6000 light years to 50,000 light years from the center of the Milky Way.”
This is an important milestone in the study of magnetic fields in space. The puzzle takes shape; although no doubt there are many more to be placed.
Source: Hiper Textual
