Most distant galaxy in the universe discovered!

http://www.smh.com.au/technology/sci-tech/most-distant-galaxy-in-the-universe-discovered-20131024-2w2r7.html



Most distant galaxy in the universe discovered!



According to Texas A&M University astronomer Vithal Tilvi, sunlight takes a little over eight minutes to reach Earth. “That means that when we are looking at the Sun, we are actually looking at the Sun as it was eight minutes ago,” he said.

The light detected from the most distant galaxy (z8_GND_5296) left it about 13.1 billion years ago. The universe was only 700 million years old when that galaxy came into being.

In other words, we are looking 95 per cent of the way back to the Big Bang. To put that into human terms, that would be like an 80-year-old watching a video of himself on his fourth birthday.

"From observing these distant galaxies, we can understand how the universe was when it was very young," Tilvi said. "There’s no other way to look into the past."

Further-away galaxies than z8_GND_5296 have been identified, but failed a double-check process along the way. The team first perused a month’s worth of images from the Hubble telescope for possible candidate galaxies.

Hubble avoids the snags that Earth-bound telescopes can run into, such as clouds and bad weather, to more easily spot the red blobs that signal a distant object.

The Doppler Effect makes the most distant galaxies appear red. Because the universe is expanding, the galaxy’s light moves away from us and gets stretched into a redder wavelength. The galaxies from within the first billion years of the universe are so far away that they have shifted into the infrared, or redder than our eyes can see…

How red the light of the object is gives some sense of how far away it is, but a technique called spectroscopy is the true litmus test that accurately confirms the distance.