National Astronomical Observatory of Japan

Subaru Telescope Detects Sudden Appearance of Galaxies in the Early Universe

| Science

A team of astronomers using the Subaru Telescope’s Suprime-Cam to perform the Subaru Ultra-Deep Survey for Lyman-alpha Emitters have looked back more than 13 billion years to find 7 early galaxies that appeared quite suddenly within 700 million years of the Big Bang. The team, led by graduate student Akira Konno and Dr. Masami Ouchi (Associate Professor at the University of Tokyo’s ICRR) was looking for a specific kind of galaxy called a Lyman-alpha emitter (LAE), to understand the role such galaxies may have played in an event called "cosmic reionization".

Figure 1
Figure 1: Color composite images of seven LAEs found in this study as they appeared 13.1 billion years ago. This represents the combination of three filter images from Subaru Telescope. Red objects between two white lines are the LAEs. The LAEs of 13.1 billion years ago have a quite red color due to the effects of cosmic expansion on their component wavelengths of light.