Galaxy z8-GND-5296 Is Most Distant Ever Seen
A red smudge of light seen by a team of astronomers was emitted from a distant galaxy around 700 million years after the Big Bang.
The red dot shows the galaxy as seen by the Hubble telescope. Pic: NASA
The most distant galaxy ever detected has been spotted by scientists studying the faint red light it emitted some 13 billion years ago.
Light from the hot cluster of stars, known as z8-GND-5296, began travelling to Earth some 700 million years after the Big Bang.
The universe was only about 5% of its current age of 13.8 billion years at the time.
Analysis of the light shows the galaxy is rich in metal and generating a surprising number of new stars.
Scientists estimate its star formation rate to be hundreds of times faster than that of our own galaxy, the Milky Way.
Astronomers first spotted the galaxy in a survey of distant objects conducted with the Hubble Space Telescope.
The research, published in the journal Nature, is based on measurements of "redshift" - the way light waves from a fast-moving object are stretched towards the red end of the spectrum as its distance increases.
A highly sensitive instrument at the Keck observatory in Hawaii, designed to detect infrared light, confirmed the galaxy's distance.
It showed the the object to have a redshift of 7.5, beating the previous record of 7.2.
Lead scientist Professor Bahram Mobasher, of the University of California, said: "By observing a galaxy that far back in time, we can study the earliest formation of galaxies.
"By comparing properties of galaxies at different distances, we can explore the evolution of galaxies throughout the age of the universe.
"With the construction and commissioning of larger ground-based telescopes ... by the end of this decade we should expect to find many more such galaxies at even larger distances, allowing us to witness the process of galaxy formation as it happens."
Scientists compare redshift with the phenomenon that causes the pitch of a police car siren to fall as its speeds away.
In the expanding universe, very distant objects are receding at a rapid rate, causing their colour spectrum to shift dramatically.
0 comments: