The biggest shockwave

A team of scientists from Caltech, USA and from the Astrophysics Department of the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg, Germany, together with other collaborators from the USA and Australia, have turned the Spitzer Space Telescope, equipped with a super-sensitive infrared spectrograph, towards the location of the group. They discovered that one of the galaxies, called NGC7318b, which is falling towards the others at high speed, is generating a giant shock wave in front of it - larger even than the Milky Way - as it ploughs its way through the intergalactic gas. The results of this amazing discovery are to be published on March 10th in a paper in the Astrophysical Journal Letters.