Old Galaxies Discovered

	Astronomers at Rutgers and Penn State universities have discovered galaxies in the distant universe, the ancestors of spiral galaxies like our Milky Way. This ancient objects, some of the first galaxies depending on the shape, is to see how they looked when the universe was only 2 billion years old. Today, researchers peg the age of the universe at 13.7 billion years, so that the light from these galaxies travelled almost 12 billion years on Earth. The newly discovered galaxies are quite small, one-tenth of the size and one-twentieth of the mass of our Milky Way. They also have fewer stars, only a fortieth as many as in the Milky Way. From ground-based telescopes, they look like single stars in size. Latest images from the Hubble Space Telescope, but they show as regions of active star formation. "Finding these objects and discover that they are a step in the development of our galaxy is akin to the search for a fossil key on the path of human evolution," says Eric Gawiser, Assistant Professor in the Department of Physics and Astronomy at Rutgers School of Arts and Sciences. The researchers found that these galaxies have been fertile ground for new stars, which burned hot and bright. These stars ionized the hydrogen atoms around them, stripping them of their electrons and that they emit a fairy tale to tell of hot-band ultraviolet light known as Lyman-alpha. The researchers also noted that several of these galaxies, sometimes 10 or more, pulled together over the ensuing few billion years into a single spiral galaxy. "The Hubble Space Telescope has striking images of these early galaxies, where 10 times the resolution of ground-based telescopes," says Caryl Gronwall, Senior Research Associate at the Penn State's Department of Astronomy & Astrophysics. "They come in a variety of shapes, round, oblong, and even somewhat linear, and we will begin to precise measurements of their size." The astronomers discovered these galaxies as part of a 5-year census of galaxies in the early universe, a project called MUSYC (multi-wavelength survey by Yale and Chile). Gawiser, while a National Science Foundation (NSF) Astronomy and Astrophysics Postdoctoral Fellow at Yale, launched a search for different types of galaxies could be a precursor of the Milky Way-spirals; Gronwall led an investigation into the luminosity, density and distribution of the distinctive Lyman Alpha-emitters. Their statistical analysis and computer simulations of galaxies, such as clusters led to the conclusion reported for the first time in December 2007: Lyman-alpha emitters are the ancestors of spiral galaxies. "We knew from our understanding of the cosmological theory that spiral galaxies had a low mass galaxies like this," said Gawiser. "The challenge is that they actually find. We'd seen other galaxies early universe, but they were bigger and, in elliptical galaxies, not spirals." The astronomers undertook four types of observations to find and characterize the objects they were looking for. It takes the first step, in fact, the Lyman-alpha-emitting galaxies midst of all visible objects of Deep Space, with the 4-meter Blanco telescope at the NSF Cerro Tololo Inter-American Observatory in Chile. To measure their distance, they used the Magellan Telescope at Las Camp Anas Observatory in Chile, for measuring the redshift, an effect that shows how fast an object from the look back on a rapidly expanding universe. (The redshift in which they studied these galaxies is 3.1.) To determine how many stars are in the galaxies, they used the NASA Spitzer Space Telescope infrared array camera. And to determine how large the galaxies, they used the NASA Hubble Space Telescope's Advanced Camera for Surveys. "Astronomy has long been a model, where large surveys, followed by detailed studies of the interesting objects they find," says Nigel Sharp, program officer in NSF's division of astronomical sciences. "This beautiful couples the large area, wide-angle field of view of our ground-based telescope with the sharp focus of the Hubble that the probe in pale light. This team has the closest yet to find young galaxies that are similar to our own Milky Way in the Infancy. "
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