By Francesco de Gasperin and Timothy Shimwell
Supermassive black holes can leave a trail of energetic particles that astronomers are able to detect using radio telescopes.
Usually the radio emission from these particles fades away and become invisible as it ages. However, in the merging galaxy cluster Abell 1033, LOFAR discovered that some of these particles can be rejuvenated and start shining again when observed at very low radio frequencies. This reenergising process can occur because when cluster merge a huge amount of energy is dissipated — these merging events are the most energetic processes since the Big Bang.
With the help of LOFAR, astronomers want to study these particles, to learn about how galaxy clusters evolve in the Universe and how their evolution is influenced by magnetic fields and accretion.