A striking image of a spiral galaxy some 67 million light-years from the Milky Way reveals the vast and complex structure of its magnetic field, believed to be related to the formation of stars and the explosion of supernovae. according to a study published this week in the journal Astronomy & Astrophysics.

Mapping the magnetic field of the galaxy named NGC 4217 was made possible by data collected by an international team of astronomers using radio telescopes in New Mexico (USA) and the Netherlands.

Specialists point out that this invisible X-shaped structure covers an extension of about 22,500 light years in space around the galaxy, extending far beyond its disk.

“NGC 4217 is of particular interest to us,” said astronomer and physicist Yelena Stein of the Strasbourg Astronomical Data Center. “This image clearly shows that when we think of galaxies like the Milky Way, we must not forget that they have magnetic fields,” he added.

Magnetic fields are generally invisible fields that exert a force on particles that are magnetically sensitive, the scientists explain.

By detecting cosmic rays on Earth, which are subatomic particles that travel through space, astronomers were able to notice the presence of these fields.

In addition to measuring the strength of the emission, they also determined how the lines of the magnetic fields are oriented.

Something “never seen before”
The team also found a helical structure and two large “superbubble” structures, originating from regions where many massive stars explode as supernovae, generating intense stellar winds.

Something “never seen before”
The team also found a helical structure and two large “superbubble” structures, originating from regions where many massive stars explode as supernovae, generating intense stellar winds.

Furthermore, scientists found something “never seen before.” They are large loop structures in the magnetic field throughout the galaxy. “We suspect that the structures are caused by the formation of stars, because at these points matter is ejected outward,” Stein said.

Although the mechanism behind the galactic magnetic fields is unclear, it is believed to be maintained by a rotating conductive fluid. On Earth, that fluid is molten iron in the core and on the Sun, it is plasma. In disk galaxies, dynamo fluid is also believed to be plasma. Astronomers hope the discoveries can serve to better study our galaxy.