National Astronomical Observatory of Japan

Discovery of an Ancient Celestial City Undergoing Rapid Growth: A Young Protocluster of Active Star-Forming Galaxies

| Science

A team of astronomers has discovered an ancient protocluster of galaxies in the midst of a vigorous process of formation. It is the densest and most active protocluster ever identified at so great a distance from Earth. The rapid construction of this young protocluster helps us to understand the early growth of clusters and the effects of a dense environment on the formation and evolution of galaxies.

These results are published in the September 20, 2012 edition of the Astrophysical Journal (Hayashi et al., 2012, ApJ, 757, 15).

Image 1
[Figure 1] A near-infrared, false-color image of the region (clump 2) where galaxies in the protocluster most strongly cluster. The objects marked with open green circles are H-alpha emitting galaxies. North is up, and east is to the left.