Researchers say cosmic sources promote the phenomenon

Apr 2, 2010 08:28 GMT  ·  By
Most galaxies, like the spiral galaxy Messier 83, pictured here, have magnetic fields. But where they come from has been a mystery
   Most galaxies, like the spiral galaxy Messier 83, pictured here, have magnetic fields. But where they come from has been a mystery

For a long time, astronomers have wondered how is it that galaxies get to be so heavily magnetized. These space structures feature strong magnetic fields that play a huge role in the way they are set up, organized, and so on. Following a new series of investigations, experts now believe they may have finally found out where these fields originate from. While looking deep into space, they noticed very strange magnetic fields simply floating about. Now, they propose that these phenomena are responsible for creating the magnetism average galaxies exhibit at this point, Space reports.

“Basically we have found some magnetic fields which are in the middle of nowhere, outside galaxies and galaxy clusters and all other known structures. People have suggested that such fields should exist on theoretical grounds, but they have never been detected before,” says Geneva Observatory in Switzerland astronomer and researcher Andrii Neronov. But the experts may have just traded one mystery for another. The origins of these precursor magnetic fields is also unknown, although their role in promoting galactic magnetism appears to have been confirmed.

According to one of two widely circulated theories on their origins, these magnetic fields may have been formed a very short period of time after the Big Bang exploded the Universe into being. Granted, when they first appeared, they were very small and weak, but over time they grew to the intensity that is currently visible to observers. The other theory states that these fields were produced by the earliest forms of galaxies, structures known as protogalaxies. Inside them, matter collided randomly, on its way to organizing itself into the shape we now usually attribute to galaxies.

According to Neronov, the second idea may actually have more merit, based on the observations he and his group conducted. The expert reveals that the magnetic fields were not observed directly. Rather, their existence was inferred from the absence of certain wavelengths of light in the areas of the sky that the group investigated. They analyzed the intergalactic medium, using the NASA Fermi Gamma-Ray Space Telescope. In some areas of the sky, much less radiation than anticipated actually exists.

It could be that the hypothesized magnetic fields are the factors deterring these particular wavelengths from being noticed from our vantage point. “At the moment we have seen some negative effects. We have seen some features which are due to the absorption of gamma-rays from distant sources,” the expert concludes. Details of the investigation are published in the April 2 issue of the esteemed publication Science.