Hubble Spots Farthest Primordial Galaxy Cluster

Hubble Spots Farthest Primordial Galaxy Cluster

Astronomers have discovered the most distant developing galaxy cluster known to date, shedding light on the formation of large-scale structure in the early universe. Researchers used NASA’s Hubble Space Telescope to find five tiny but bright galaxies clustered together 13.1 billion light-years from Earth. That means Hubble is observing them as they existed just 600 million years after the Big Bang, the dramatic event that brought our universe into existence. According to Michele Trenti, of the University of Colorado at Boulder and the University of Cambridge in the United Kingdom these galaxies formed during the earliest stages of galaxy assembly, when galaxies had just started to cluster together.

Hubble spotted the five galaxies while performing a random sky survey in near-infrared light. According to researchers the newfound galaxies are small, ranging from 10 percent to 50 percent the size of our own Milky Way. But they’re about as bright as the Milky Way, because they’re feasting on huge amounts of gas via mergers with other galaxies. Hubble’s new discovery offers a rare chance to observe ancient protoclusters, which are dim and widely scattered across the sky. The new find helps demonstrate that galaxies build up progressively over time. It also provides further evidence for the hierarchical model of galaxy assembly, which posits that small objects merge to form bigger ones in a steady process of collision and accretion.The scientists estimated the distance to the newfound protocluster based on their colors, but they plan to follow up with spectroscopic observations, which measure the expansion of space. Those measurements will help pin down the cluster’s precise distance.
source:www.nasa.gov