Deep-space magnetic fields described

LOS ANGELES, Sept. 21 (UPI) -- Evidence of "universal ubiquitous magnetic fields" permeating deep space between galaxies since the Big Bang has been discovered, U.S. astronomers say.

For many years physicists have hypothesized a universal magnetic field should exist in deep space between galaxies, but there was no way to observe it or measure it until now.

Caltech physicist Shin'ichiro Ando and UCLA astronomer Alexander Kusenko studied images of the most powerful objects in the universe -- supermassive black holes that emit high-energy radiation as they devour stars in distant galaxies -- obtained by NASA's Fermi Gamma-ray Space Telescope, a UCLA release said.

After producing a composite image of 170 giant black holes, they discovered the images were not as sharp as expected.

Background radiation left over from the Big Bang could account for some -- but not all -- of the distortion, they said.

But "even a small magnetic field along the way can deflect the electrons and positrons, making the image fuzzy," they said.

Using the images, they calculated the average magnetic field as just one-quadrillionth the strength of Earth's field.

This universal magnetic field may have formed in the early universe shortly after the Big Bang, long before stars and galaxies formed, Ando and Kusenko said.