Hot on the heels of its historic 25th birthday, the Hubble Space Telescope—with help from NASA's Spitzer Space Telescope. and the W.M Keck Observatory—has stumbled across the most distant galaxy to date.
Known as EGS-zs8-1, this distant source of light first formed nearly 13 billion years ago, when the universe was roughly 5 percent of its current, 13.8-billion-year age. Despite its distance, it remains one of the brightest and most massive galaxies in the distant universe—only we're seeing it at an early stage in it, and the universe's, evolution.
“It has already grown more than 15 percent of the mass of our own Milky Way today,” said Pascal Oesch, lead author of the study. “But it had only 670 million years to do so. The universe was still very young then.”
In fact, when the foundation of EGS-zs8-1 was laid, the universe was in the midst transitional phase—the first was the time in which protons and electrons began to combine and forge neutral hydrogen atoms; The second—known as the epoch of reionization—occurred when new generations of stars ionized the atoms, leaving them in a more excited state.
The international team of researchers—led by astronomers from the University of California and Yale University—plucked EGS-zs8-1 from a preexisting data pool, which was collected for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS ).This image combines observations taken by Spitzer and Hubble, and the Hawaiian W.M Keck Observatory was used to confirm its distance from planet Earth. Ultimately, determining the precise distance to an object located in the most distant reaches of space is a complicated process (often dealing with redshift), with only a tiny number of galaxies this distant ever having been measured to date.
Measurements of record-setting-galaxy EGS-zs8-1 were only made possible by a powerful tool installed on Keck in 2012—the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) instrument; a near-infrared multi-object spectrograph that effectively increased the telescope's firepower to the point that it now allows astronomers to glean insight on multiple galaxies simultaneously.
"The new distance measurement also enabled the astronomers to determine that EGS-zs8-1 was still forming stars very rapidly, about 80 times faster than our Milky Way galaxy today (which has a star formation rate of one star per year)," NASA revealed in their press release. They continue: