Astronomers from New Mexico and the Netherlands have obtained an image of the magnetic field of the galaxy NGC 4217. It is located 67 million light years away, belongs to the spiral type and is turned sideways to us. Thanks to this, its magnetic field, which extends around the galaxy for 22.5 thousand light years, looks even more spectacular, even if it cannot be seen with a human eye.
To detect such fields, synchrotron radiation is used, which is generated as a result of the contact of cosmic rays and the magnetic region around the galaxy. It is interesting for scientists because it allows you to measure not only the strength of the magnetic field, but also the polarization of the waves – that is, to determine how they are oriented. Thanks to this, scientists discovered that the shape of the magnetic field of NGC 4217 is cruciform.
Further observations revealed in the structure of the galactic field the presence of two huge “superbubbles”, which are characteristic of the places of death and birth of stars. And in the field of NGC 4217, huge magnetic loops of unknown origin are observed. At the same time, the total field strength is rather modest – 0.9 microgauss, against 0.5 gauss near the Earth.
Most of the controversy among scientists is about the origin of magnetic fields in galaxies. The basic circuit is based on the presence of an electrically conductive fluid that converts kinetic energy into magnetic energy. The Earth’s liquid medium is its molten core, the Sun has plasma, but what replaces them on the scale of the galaxy? There is a version that the matter is forced to move by supernova explosions and the Coriolis force, and the compressing gas creates turbulence and inhomogeneity of the system.