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The oldest galaxies

The oldest galaxies in the early Universe

 Automatic translation  Automatic translation Updated June 01, 2013

Only 480 million years after the Big Bang, galaxies existed. The Hubble Space Telescope has discovered a galaxy that would have existed in the early universe. A study published January 26, 2011 shows the distant past of the cosmos. We see the light of a galaxy spotted by Hubble in the infrared, the emitted light was there 13.2 billion years. At that time the Universe was only 4% of its present age, Rychard Bouwens specify (UC) and his team.
"This is the limit of our possibilities, but we have spent months for tests to confirm it and we are now confident enough of us," notes Professor Garth Illingworth, a co-author of the study.
"We go up close to the time of the first galaxies, which were formed some 200 to 300 million years after the Big Bang," he says in a statement from the University of California. Light captured by telescopes, after traveling at the speed of light that is 300 000 km/second, for more than 13 billion years, shows us the first tremors of our universe. The electromagnetic radiation from this period have a wavelength which shifts more towards red. This redshift is used to measure the travel time of light. More light is old, over the redshift is large.


Hubble UltraDeep 2009 (HUDF09) is a project conceived in 2007. Through displays of several days, HUDF09 captures images of the universe in the infrared and so astronomers can watch the universe when it was younger. They then analyze the first light of primordial galaxies, only 600 million years after the Big Bang.
To see our Universe even further in the past, it was not until the launch, expected in 2014, the James Webb Space Telescope.

Image: Little light of the galaxy UDFj-39546284, already present there are 13.2 billion years, 600 million years after the Big Bang. Image of the Hubble Space Telescope (2011).

 HUDF09 the oldest galaxy in the universe

Galaxy BX 442 (10.7 billion years)


Large elliptical and spiral galaxies, the brightest and best defined, are the closest, they are barely a billion light years from our galaxy, i.e. when the universe was already older than 13 billion years.
Our universe is really big.
This is still the Hubble Space Telescope has offered to Alice Shapley and colleagues at the University of Toronto, an incredible view of the galaxy BX442, published in the journal Nature. This galaxy 10.7 billion years, among 300 other very distant galaxies, is a spiral galaxy despite its age. The task of the researcher was conducting a study on generating galaxies of stars from the beginning of the universe, about 10.7 billion light years.
"And then, without warning, BX442 arose the image with its spiral structure, we could not believe it! We do not expect a form as beautiful as the overwhelming majority of the galaxies early universe are highly irregular and lumpy, "said Alice. This discovery is surprising because until now, astronomers believed that the old galaxies in the early Universe (about 3 billion years after the Big Bang) were completely disorganized, irregular. BX442 therefore show an organization in spirals like our own Galaxy, the Milky Way. In this representation of the Hubble Space Telescope data, we can see, in addition to the galaxy BX442, an irregular galaxy (upper image) that appears to be attracted by the old spiral galaxy. This discovery shows that there are 11 billion years, the first spiral galaxies were formed already. The early universe, has not ceased to astonish researchers. Although the spiral structure and rotation have been confirmed, the reason for the spiral structure remains a mystery. Why this galaxy was able to form such structures in spiral much earlier than other galaxies of similar age in the early Universe?


One possibility being considered is the presence of a small companion galaxy, a dwarf galaxy that scientists observe in the process of merging with the main galaxy.
A dwarf galaxy could promote the formation of the spiral structure of the main galaxy.
image BX442 seen by Hubble

Image: Spiral Galaxy BX442 located at 10.7 billion years. Image of the Hubble Space Telescope (HST). HST/Keck false color composite image of the galaxy BX442. Credit: David Law / Dunlap Institute for Astronomy & Astrophysics.

 galaxy cartwheel

Image: Spiral Galaxy BX442 located at 10.7 billion years. Artist Image reworked from Hubble image below cons. (Dunlap Institute for Astronomy & Astrophysics - Joe Bergeron), July 19, 2012.

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