Looking back at 11 billion years ago, astronomers for the first time measured the motion of stars of a distant galaxy and obtained a velocity of up to one million miles per hour, twice the heaven in the Milky Way.
Large-speed stars are revealing how distant galaxies are about the size of a Milky Way that has the shape we see today. The findings will be published in this August 6 issue of Nature.
'This galaxy is very small, but the stars move at tremendous speeds as if they were members of a great galaxy today right next to our Milky Way,' said Pieter van Dokkum. The physicist-astronomer at Yale University, Connecticut, said the team leader. It is still unclear why these galaxies, such as large and small in size, can form in the early universe and then develop into galaxies that we see right next to the Milky Way. Ha today is about 13.7 billion years old.
The work of the international research team combined the data collected from NASA's Hubble Space Telescope with observations from the Gemini South telescope in Chile. According to van Dokkum, 'Hubble's glass data in 2007 confirmed that this galaxy is only a fraction of the size of most older, more mature' galaxies that we see today. The Gemini telescope's 8-meter-long mirror allows gathering enough light to determine the movement of stars with a technique similar to the way police use laser light to fire vehicle speeds. ' Observation with near-infrared spectroscopy takes 29 hours in a row to collect very light from the distant 1255-0 galaxy.
'With these observations, we can turn back time and know how ancient galaxies look when the universe is very young,' said Mariska Kriek, Princeton University lecturer, team member. study said. NJ 1255-0 existed long ago, when the universe was only 3 billion years old.
Astronomers confess that it is difficult to explain how such small mass galaxies have formed, and why they do not appear in the universe today.'One possibility is that what we're seeing now will later become the concentrated center of a huge galaxy,' said Marijn Franx of Leiden, another member of the research team. 'The central part is probably the first formed part along with giant black holes that exist in large galaxies today.'
To test the formation of extremely large galaxies, astronomers plan to carefully observe the more distant galaxies. With the new 3 wide field camera installed on the Hubble Space Telescope, these galaxies can be detected.'The ancestors of massive galaxies must have very different properties because they form a lot of stars and a large black hole in a relatively short time,' van Dokkum said.
This study follows previous studies that suggest that the oldest, most luminous galaxies in the early universe are small but starred galaxies comparable to today's elliptical galaxies. The largest mass galaxies we see in the universe today have a relative mass of 1255-0 and are usually about five times larger than the young, small galaxies.
Hubble Space Telescope observations were conducted with near-infrared cameras and multi-form spectrometer (NICMOS).
The observations from the Gemini telescope were conducted with the near infrared spectrophotometer (GNIRS), the device is currently being upgraded and will be re-installed on the North Gemini telescope in 2010.