ICTS

A team of ICTS researchers have explained the observed early generation of coherent magnetic fields in galaxies at high redshift using theory and simulations. 

 

Most visible matter in the universe exists as plasma — an electrically conducting gas of charged particles. As this plasma moves, it can convert kinetic energy into magnetic energy through a process known as a dynamo. In mature galaxies, dynamos driven by disk rotation and turbulent motions are thought to amplify magnetic fields over billions of years. Yet, recent astronomical observations suggest that young galaxies can already host strong magnetic fields.

 

Muhammad Irshad, Pallavi Bhat and their collaborators Kandaswamy Subramanian and Anvar Shukurov have shown how such rapid magnetization may occur. The researchers demonstrated that during the violent gravitational collapse of a protogalactic plasma cloud, turbulence is intensified in a way that dramatically accelerates dynamo action. By reformulating the equations of magnetized fluid flow in coordinates that naturally account for cosmic expansion or contraction, they model a collapsing cloud and find that magnetic fields can grow even faster than exponentially. The acceleration of large-scale turbulent eddies during collapse acts as a powerful catalyst, enabling strong magnetic fields to emerge on much shorter timescales than previously expected.

 

The work was published in Physics Review Letters (Turbulent Dynamos in a Collapsing Cloud, Phys. Rev. Lett. 136, 091201). It was also showcased with an article titled Gravitational Collapse Primes Galactic Magnetism in the Physics magazine.