Figure 26-22: R I V U X G
A Galaxy Under Construction This Hubble Space Telescope image shows dozens of small galaxies in the process of merging into a single large galaxy. We see this galaxy at a redshift z = 2.2, corresponding to a time 3.1 billion years after the Big Bang.
(NASA; ESA; G. Miley and R. Overzier, Leiden Observatory; and the ACS Science Team)