Astronomers discover ancestors of Milky Way-type galaxies

January 9th, 2008 - 1:51 pm ICT by admin  

Washington, Jan 9 (ANI): Astronomers have discovered galaxies in the distant universe that are ancestors of spiral galaxies like our own Milky Way.

Discovered by astronomers at Rutgers and Penn state universities, these ancient objects, which were some of the first galaxies ever to form, were observed as they looked when the universe was just two billion years old.

The researchers noted that several of these galaxies, sometimes 10 or more, pulled together over the ensuing few billion years to form a single spiral galaxy.

We knew by our understanding of cosmological theory that spiral galaxies had to evolve from low-mass galaxies such as these, said Eric Gawiser, assistant professor in the Department of Physics and Astronomy in the Rutgers School of Arts and Sciences. The challenge was to actually find them. Wed seen other early universe galaxies, but they were bigger and destined to evolve into elliptical galaxies, not spirals, he added.

The Hubble Space Telescope has delivered striking images of these early galaxies, with 10 times the resolution of ground-based telescopes, said Caryl Gronwall, senior research associate in Penn States Department of Astronomy & Astrophysics.

According to Gronwall, these galaxies come in a variety of shapes round, oblong, and even somewhat linear and scientists are now starting to make precise measurements of their sizes.

The newly discovered galaxies are quite small one-tenth the size and one-twentieth the mass of our Milky Way. They also have fewer stars only one-fortieth as many as are in the Milky Way.

Though they look like individual stars in size from ground-based telescopes, recent images made by the Hubble Space Telescope, however, revealed that they were fertile breeding grounds for new stars, which burned hot and bright.

Finding these objects and discovering that they are a step in the evolution of our galaxy is akin to finding a key fossil in the path of human evolution, said Gawiser.

This team has come the closest yet to finding young galaxies that resemble our own Milky Way in its infancy, said Nigel Sharp, program officer in NSFs Division of Astronomical Sciences. (ANI)

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