by The earth has a magnet. Our sun has a magnet. Our Milky Way galaxy is magnetized. And some galaxies have magnetic fields, too. On September 6, 2023, astronomers using the ALMA telescope in the Atacama Desert in Chile claimed to have identified the most distant magnetic field of the galaxy to date. The galaxy goes by the very cool name of 9io9. Its light has to travel more than 11 billion years to reach us, from the time when the universe was 2.5 billion years old.
You can see the magnetic field of 9io9 in the new image above. It looks like a blue arc with bright spots.
Journal Nature will publish a research paper for these scientists. Until then, you can access the previous edition on the website of the European Southern Observatory.
Galaxies have magnetic fields, too
As lead author James Geach, an astrophysicist at the University of Hertfordshire, UK, noted, it may not be common knowledge that galaxies have magnetic fields. And they are big. He said:
Many people may not realize that our entire galaxy and other galaxies are filled with magnetism, spanning tens of thousands of light years.
And despite what astronomers know about galactic magnetic fields, much remains to be learned. Co-author Enrique Lopez Rodriguez, a researcher at Stanford University, added:
We actually know very little about how these fields form, although they are fundamental to how galaxies evolve.
The Galactic magnetic field is the most distant ever observed
Part of the reason we don’t fully understand how galactic magnetic fields are formed is because of the distance and difficulty of observing them. Until now, astronomers have mostly studied magnetism in the galaxies closest to us. But to find out how these magnets are built in the first place; Astronomers must see people much older and far away from us. That’s where ALMA comes in.
Using this powerful radio telescope, researchers have discovered a magnetism in a galaxy far more distant than anything they’ve seen before. It appeared to be similar to the magnetism in the galaxies near us. And it’s not just far, it’s huge, stretching over 16,000 light years across. Wow! However, despite its size, the galaxy’s magnetism is weak. This is 1,000 times weaker than the Earth’s magnetism. So, as the saying goes, size isn’t everything.
You can “zoom in” on galaxy 9io9 in the video below:
As for the galaxy itself, viewers of the BBC’s Stargazing Live television program discovered the 9io9 galaxy as part of a citizen science project. They hunted for distant galaxies in millions of scientific images over three nights in 2014, a task that placed target galaxies for astronomers to study further.
Using galactic dust grains to find the magnetic field
The research team discovered the galaxy’s magnetic field by examining the light emitted by dust grains in the galaxy. Just as atoms in ferromagnetic materials will “line up” together when influenced by a magnet, dust grains in galaxies will align in the presence of a magnet. The dust grains then emit white light. That light is different from other light sources because it only travels in one direction. So if a galaxy emits this kind of polarized light, that’s evidence of a galactic magnetic field.
How does a galaxy’s magnetism occur?
Since this galaxy emits this magnetism from a distance and is old, this discovery may provide information on how the magnetic field develops. Geach said:
This discovery gives us new clues about how galactic-scale magnetic fields are created.
This page also says:
Magnetic fields are important for the evolution of galaxies, playing a key role in the astrophysics of the interstellar medium (ISM) and star formation. Large-scale organized magnetic fields have been mapped in the Milky Way and nearby galaxies, but it is not known how early these structures are in the universe.
Stars and galaxies interact with each other
Another thing you’re picking up is that the magnet seems to be growing fast. This is based on the fact that the magnetic field has been fully formed at an earlier time in the history of the universe (and its galaxy). So, how do these magnetic fields grow so quickly? Researchers say it has something to do with star formation. This happened in the very beginning, when the universe was very young. And what goes around, goes around. The newly formed magnetic field, in turn, influences the formation of future stars. As ESO historian Rob Ivison noted, the discovery:
… opens a new window into the inner workings of galaxies, because magnetic fields are associated with the material that forms new stars.
These findings will provide scientists with new insights not only into how magnetic fields form and function on scales much larger than those anywhere in our solar system, but also how they have affected the evolution of galaxies throughout the universe. From when we played with magnets as children to galactic “magnets” that travel thousands of light years away, it’s a new cosmic look at an ordinary natural phenomenon.
Background: Astronomers using the ALMA telescope have discovered the most distant magnetic field ever observed by scientists. It existed when the universe was only 20% of its current time.
Source: Polarized thermal emission from dust in a galaxy at red-shift 2.6
With ESO
Through ALMA
Read more: Galaxies have magnetic fields, too! Pictures here
Read more: Center of the Milky Way: Threads of hot gas and magnetism
#farthest #point #galactic #magnetic #field #galaxy #9io9
