The Coma Great Wall

Discovered around 1989 in the CfA2 galaxy redshift survey, the Coma Great Wall is important historically for cementing the idea of the filamentary cosmic web in astronomy. This survey (in the sense of a mapping effort), headed by Margaret Geller and John Huchra, provided an unprecedented 3D map of a slice of the Universe. It is famous for a “stick figure," evident in one of the pictures. The stick figure is headless in our model, since its head, part of the Coma Cluster of galaxies (thousands of galaxies behind the Coma Berenices constellation) may well be an artificial “Finger of God." These maps are provided mainly by galaxy redshifts -- we estimate how distant a galaxy is by how fast it is moving away from us (according to Hubble’s Law, indicating the expansion of the universe). But clusters of galaxies are like swarms of bees, many of the galaxies inside moving faster than the cluster away from us, appending a head to the stick figure.

 This model was designed to be as scientifically accurate to our real Universe as possible, by experts in the field, Prof Miguel Aragón (UNAM, Ensenada, Mexico), and also helping, Dr Mark Neyrinck (Ikerbasque Asst Research Prof, Bilbao, Spain.) It uses galaxy positions from SDSS, and a new, simple yet sophisticated technique of inferring the cosmic web of filaments from galaxy positions. And it makes a great Christmas ornament!