The 'Perseus Cluster' (Abell 426) of galaxies contains approx 500 members and is located around 250 million light years from earth. The dominant central galaxy in the image is a NGC 1275, a Syfert type elliptical and second most powerful radio source next to Centaurus A.

It is theorized that immense gravitational forces at center of this cluster (over 400 trillion solar masses) compress gasses to tremendous densities & temperatures, one product of which is the emission of x-rays.

Recent Hubble observations have shown NGC 1275 to be a merger of two galaxies - an elliptical and a spiral - where a single pass of this gravitational dance can take as long as 100 million years, and the intense tidal forces at play spark star formation activity including spawning spectacular globular clusters similar in form, but much younger than those in our own Milky Way galaxy.

The Perseus-Picses Supercluster, of which A426 is a member, is one of two dominant galactic concentrations in the 'nearby' universe. One one side of our local superclusters lies Perseus-Pisces, on the other is the Hydra-Centaurus cluster and the 'The Great Attractor', the most significant concentration of dark/unseen matter yet discovered. It's gravitation is causing a significant flow of matter towards it, creating a gravitational tug-of-war with the Perseus-Pisces Supercluster, finding our Local Supercluster at the center.

mass density region of our 'local' universe (300 million light year range)