Ultra-steep spectrum emission in the merging galaxy cluster Abell 1914

Understand

A number of radio observations have revealed the presence of large synchrotron-emitting sources associated with the intra-cluster medium.

• There is strong observational evidence that the emitting particles have been (re-)accelerated by shocks and turbulence generated during merger events.
• The particles that are accelerated are thought to have higher initial energies than those in the thermal pool but the origin of such mildly relativistic particles remains uncertain and needs to be further investigated.
• The galaxy cluster Abell 1914 is a massive galaxy cluster in which X-ray observations show clear evidence of merging activity.