High-energy plasma

An image revealing the age of high-energy plasma in Stephan’s Quintet, as captured by radio observations with the VLA and LOFAR. The blue colours indicate older, low-energy plasma, while the orange and yellow areas mark regions that are being actively energised. The thin, dashed lines outline the location of the galaxies in the group, while the black solid lines trace the shock region identified with WEAVE data, which perfectly matches the areas where this plasma is being re-accelerated by the collision between NGC 7318b and the group.