Australasian Science: Australia's authority on science since 1938

The Origin and Evolution of Cosmic Magnetism

The giant radio galaxy Hercules A.

Figure 1. The giant radio galaxy Hercules A. Radio synchrotron jets emerging from the optical host of the galaxy mark the presence of magnetic fields roughly 1 million light-years in scale. Credit: NASA, ESA, S. Baum and C. O'Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA)

By Melanie Johnston-Hollitt

Understanding the origin and evolution of magnetic fields in the universe is one of the great challenges of modern astrophysics. The unique capabilities of the SKA will provide astronomers with the best tools to explore how, when and where magnetic fields in the cosmos formed.

The full text of this article can be purchased from Informit.

Most people are familiar with magnets, usually in the form of the ubiquitous fridge magnet, which is bound tightly to your refrigerator by a magnetic field. Many people will also know that the Earth possesses a global magnetic field that is generated by the motion of iron-rich material in the depths of the planet.

What is perhaps more surprising is that the entire universe is filled with magnetic fields, that these fields are in many ways still a mystery, and that we have yet to address fundamental questions about their origin, strength and evolution. Fortunately, the mysteries of these cosmic magnetic fields are about to be solved as the Square Kilometre Array (SKA) radio telescope provides us with the first glimpses into the depths of the hidden magnetised universe.

The origin and evolution of cosmic magnetism is one of the great unsolved problems of modern astrophysics. In fact, so important and fundamental are the questions concerning magnetism that they touch almost every aspect of modern astronomy. For example, we do not yet know how magnetic fields first arose in the universe, nor if these fields arose over the entire universe simultaneously, allowing individual objects to become more magnetised over time through a process known as amplification, or if small pockets of magnetism formed in individual astronomical objects that then spread magnetism out...

The full text of this article can be purchased from Informit.