Most Distant Galaxy Discovered Far, Far Away


Mimi Liu

An international team of astronomers has just discovered the furthest galaxy from humans: z8_GND_5296, 30 billion light years away.

“This is the most distant galaxy we’ve confirmed,” said lead researcher Steven Finkelstein from the University of Texas at Austin.

This galaxy formed 700 million years after the Big Bang, allowing scientists to glean more information regarding the solar system immediately after the creation of the universe. z8_GND_5296 still appears as it existed 13.1 billion years ago, as light waves take time to arrive at Earth. The universe is constantly expanding, however, so x8_GND_5296 is now actually a total of 30 billion light years away.

The constant expansion of the universe also means that light waves stretch as they reach Earth, causing star systems seem redder than they really are. Scientists have determined that this galaxy has a redshift rating of 7.51, the highest discovered to date.

z8_GND_5296 was spotted with the Hubble Space Telescope, and confirmed with the instruments at the Keck Observatory in Hawaii. The Hubble Space Telescope had infrared hardware added to it in 2009, for Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS), a month-long scan of galactic systems in deep space.

“One very interesting way to learn about the Universe is to study these outliers and that tells us something about what sort of physical processes are dominating galaxy formation and galaxy evolution,” said Finkelstein.

Over 100,000 galaxies were discovered with this method, and the likely candidates were narrowed down to a mere 43.

This system is small, about 1 to 2 percent of the mass of the Milky Way, but it produces stars at a rate 150 times faster than that of our own galaxy. The Milky Way potentially produces about one or two sun-like stars each year, but z8_GND_5296 created about 300 each year, when the universe was only 700 million years old.

“This is an important step forward, but we need to continue looking…the further away we go, the closer we will get to discovering the very first stars that ever formed in the Universe,” adds Professor Alfonso Aragon-Salamanca from the University of Nottingham.

Cosmologists will continue searching for the answers to seemingly unanswerable questions. For example, the stars, and the rate they were produced at in various galaxies could tell us exactly when hydrogen went from a neutral to a charged form.

Hydrogen is the most abundant element in the universe, and discovering the reason behind this fundamental charge shift could mean being another step closer to answering the important questions, such as how exactly our universe was created, how our laws of physics formed, and whether there could be other life-supporting star-systems in the universe.

However, this research would require at least 10 more galactic discoveries before scientists can gather the data necessary to come to any kind of a conclusion.

“This work shows that, with new technology, it has finally become possible to make significant advances in the detection of yet more distant galaxies,” Dominik Riechers, an astronomer says.

Hopefully the Giant Magellan Telescope, a massive 25m diameter telescope, will help with future astronomical endeavors. It’s currently being built in Chile and expected to be taken online in 2020.