I am in the second year of a PhD in astrophysics, studying binary supermassive black holes with Martin Krause at the University of Hertfordshire, based in the Centre for Astrophysics Research. Supermassive black holes (SMBHs) are found in the centre of almost every galaxy. There are hundreds of billions of galaxies — like the Milky Way in which we live — in our universe, and mergers between them are common. It follows that there may be two or more SMBHs in the heart of every galaxy.

Understanding such systems is not straightforward. Black holes, by their very nature, cannot be studied directly. Instead, we have to study the systems around them, such as accretion disks or radio jets.

My research focuses on the dynamics of radio jets. These are large structures in space, emitted by powerful supermassive black holes found in the centre of galaxies. Radio jets can be millions of light-years across, such as the well-studied jets in Cygnus A, as shown below.


These jets are formed by accretion onto supermassive black holes. If you look closely you can see a lot of structure in the jet and lobe. These are caused by both the jet itself and interactions with the environment around it. Space is not empty! Think of a water fountain on a windy day. The wind might push the water slightly in one direction, and you can measure that change even if you can’t directly see the wind.

You might think that a huge jet emerging from a galaxy has nothing in common with a water fountain, but that’s not quite true. The physics of a fountain is governed by hydrodynamics (HD), and radio jets are governed by relativistic magneto-hydrodynamics (RMHD). The magneto part, like the X-Men character of the same name, are related to strong magnetic fields. Northern Lights are produced by magnetodynamics!

In the case of my research, the magnetic fields are produced by massive black holes. The relativistic part is because material is accelerated close to the speed of light, and so Einstein’s theory of relativity plays a role.

It can sound a bit scary, but if you can understand a water fountain (or even a jet from a water gun!!) then it is only a few more steps to understand the enormous processes occurring in the depths of space. We are all part of the same universe, after all.

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