A cluster of distant stars formed some 13 billion years ago are discovered to be infant galaxies, astronomers showed in a Liverpool presentation on Tuesday.
Using far-reaching telescopes that act as time machines, astronomers were able to date back clusters of distant stars forming at least 4,000 galaxies that have evolved similarly to the Milky Way.
Scientists measured the so-called redshift, a light that is emitted by stars, to measure its distance from Earth. The reddish color of the light is due to the galaxies stretched out by the expansion of the universe.
State-Of-The-Art Telescopes
The team led by Dr. David Sobral, a professor of Lancaster University, used the Subaru telescope in Hawaii and the Isaac Newton telescope in the Canary Islands to map star wavelengths.
"These early galaxies seem to have gone through many more 'bursts' when they formed stars, instead of forming them at a relatively steady rate like our own galaxy," Sobral said.
Coauthor Sergio Santos, who is a PhD student at Lancaster, further explained that they used 16 special filters on wide-angle camera lenses and then sliced the images to match the cosmic time.
What is even notable about Sobral's findings is that these infant galaxies were compact and measure about 3,000 light-years in size, which is 30 times smaller than the Milky Way.
Experts said the physical properties of these young galaxies are the gateway to learn about how the Milky Way has evolved billions of years ago.
Expanding Galaxy
Scientists think that the galaxies similar to Milky Way, which measures about 100,000 light-years, is expanding at a rate of 550 yards per second.
Although the growth in size will not have any noticeable difference in the near future, researchers said the Milky Way is expected to be 5 percent bigger than it is today.
"The Milky Way is pretty big already. But our work shows that at least the visible part of it is slowly increasing in size, as stars form on the galactic outskirts," said Cristina Martinez-Lombilla, a PhD student at the Instituto de Astrofísica de Canarias in Tenerife, Spain.
Since galaxies are made of disks packed with young blue stars, scientific models predict that it is expected to expand over time. Similar to Sobral's strategy, Martinez-Lombilla's team used land-based space telescopes to collect data that showed how the blue stars moved around the disks.
However, astronomers said the Milky Way will not grow infinitely, as it is expected to collide with Andromeda Galaxy 4 billion years into the future. This phenomenon will consider the current size of these galaxies irrelevant.
