Discover the source of the magnetic fields of the universe

Columbia University researchers have discovered that magnetic fields across the universe may arise from turbulent plasma. Their study shows that these plasmas, present in different environments, can spontaneously form and amplify magnetic fields, revealing the process by which magnetic fields can extend over enormous distances.

The source of magnetic fields has long been debated. New research provides clues to their origins.

It’s not just your refrigerator that has magnets. Earth, stars, galaxies, and the space between galaxies are also magnetized. The more places scientists have looked for magnetic fields across the universe, the more they’ve discovered. But the question of why this is so and where these magnetic fields originate from has remained a mystery and a subject of ongoing scientific research.

The magnetic field in the whirlpool galaxy (M51) was captured by NASA’s Flying Stratospheric Observatory for Infrared Astronomy (SOFIA) superimposed on a Hubble Telescope image of the galaxy. The image shows infrared images of dust grains in the M51 galaxy. Their magnetic orientation largely follows the spiral shape of the galaxy, but is also pulled in the direction of the neighboring galaxy to the right of the frame. Credit: NASA, Sophia Science Team, a. Burlough; NASA, ESA and S. Beckwith (STScI) and Hubble Heritage Team (STScI/AURA)

Insights into the origins of the magnetic field

A new paper by Columbia scientists provides insight into where these domains come from. The research team used models to show that magnetic fields may arise spontaneously in the case of disturbances plasma.

Plasma is a type of matter found mostly in extremely hot environments such as those near the surface of the Sun, but plasma is also scattered throughout the universe in low-density environments, such as the expanse of intergalactic space; The team’s research focused on those low-density environments.

Their simulations showed that, in addition to generating new magnetic fields, perturbation of these plasmas can also amplify magnetic fields once they are generated. This helps explain how magnetic fields that arise on small scales can eventually reach the extent of vast distances.

Composite image showing the birth and growth of magnetic fields in turbulent plasmas, from weak fields on small scales (top left) to strong fields on large scales (lower right). Credit: Columbia University

“This new research allows us to imagine the kinds of voids that generate magnetic fields: Even in the most pristine, vast, and remote spaces of our universe, plasma particles bogged down in turbulent motion can spontaneously generate new magnetic fields,” Cerrone said.

“The search for a ‘seed’ that can seed a new magnetic field has been a long time coming, and we are excited to provide new evidence for this original source, as well as data on how the magnetic field grows, once it is born.”

Reference: “Generation of Quasi-equivalent Magnetic Fields in Turbulent, Non-colliding Plasmas” by Lorenzo Cerrone, Luca Comiso, and Ryan Gollant, 31 July 2023, Available here. Physical review letters.
DOI: 10.1103/PhysRevLett.131.055201

The paper was written by astronomy professor Lorenzo Cerrone, astronomy research scientist Luca Comiso, and astronomy doctoral candidate Ryan Gollant.