A team of astronomers including astronomers from the University of Tokyo mapped theDiagram of the magnetic field structure within the spiral arms of the Milky Way. Previous studies have provided only a rough overview of the Milky Way's magnetic field. However, this novel study found that the magnetic fields within the galactic spiral arms significantly deviate from this broad overview, showing a significant tilt from the galactic mean magnetic field. These findings indicate that magnetic fields have a significant influence on the regions where stars form, meaning magnetic fields played an important role in the formation of the solar system.

Some people may be surprised by the existence of magnetic fields, which are larger than Earth. Most of the magnetic fields we come into contact with every day are sticking things on the refrigerator or using a compass to point north. The latter shows the presence of a magnetic field generated by our planet. Our sun also produces a huge magnetic field, which affects phenomena such as solar flares. But the magnetic fields that span the entire galaxy are almost too large to comprehend, but they likely play a role in the formation of stars and planets.

"So far, all observations of the magnetic field within the Milky Way have been made within a very limited model that is uniform and consistent and largely matches the disk shape of the Milky Way itself," said Yasuo Doi, assistant professor in the Department of Earth Sciences and Astronomy. "Hiroshima University's telescope facility is able to measure polarized light, helping us Determining the magnetic field signatures, and the Gaia satellite launched by the European Space Agency in 2013, which specializes in measuring the distances of stars, helped us build a better model with finer three-dimensional detail. Focusing on one specific region, the Sagittarius arm of our spiral galaxy (we are in the neighboring Orion arm), we found that the dominant magnetic field there is significantly deviated from the plane of the galaxy. "

The white lines superimposed on this image of the Sagittarius Arm of the Milky Way galaxy show the polarization, or direction, of light. This is related to the direction of the local magnetic field lines. Combining this information allows a detailed map of the magnetic field of this arm of the Milky Way. Source: 2023Doietal.

Previous models and observations could only imagine the existence of a smooth and essentially uniform magnetic field in the Milky Way; the new data show that while the magnetic field lines in the spiral arms are roughly aligned with the Milky Way on large scales, on small scales these magnetic field lines are actually spread out at different distances due to the influence of various astrophysical phenomena such as supernovae and stellar winds.

The Milky Way's magnetic field is also very weak, about 100,000 times weaker than the Earth's own magnetic field. Still, over long periods of time, gas and dust in interstellar space are accelerated by these magnetic fields, which explains the emergence of star nurseries -- star-forming regions -- that gravity alone cannot explain. The discovery means further mapping of the magnetic field within the Milky Way could help better explain the nature and evolution of the Milky Way and other galaxies.

"I am personally very interested in the fundamental processes of star formation that are critical to the creation of life, including our own," Doi said. "The goal is to further observe and build better models of the structure of the Milky Way's magnetic field. This work aims to gain observational insights into the accumulation of gas that fuels active star formation in the Milky Way and its historical development."

Compiled source: ScitechDaily