Yillara Skye 1 Posted April 13, 2003 I found this at Astronomy.com, and I figured I would post it here if anyone is interested in viewing the article. It is about the discovery of several galaxies once thought to be young, when in fact they are from when the universe was much younger.... Key to Galaxy Mystery Revealed by Redshift Recent redshift determinations put submillimeter galaxies in their place. by Pamela L. Gay In 1997 astronomers discovered a population of galaxies that were extremely faint and that appeared most luminous at submillimeter wavelengths. Astronomers have suspected that these are young galaxies so rich in dust that the light from their stars is mostly obscured. To prove this hypothesis, however, astronomers needed redshift measurements. Now, thanks to observations done by Ian Smail of the University of Durham and colleagues, the redshifts for a sample of submillimeter galaxies are known, and with them, the galaxies' place in the very distant universe has been confirmed. Using the Low Resolution Imaging Spectrograph on the 10-meter Keck I Telescope at Mauna Kea, the astronomers identified strong emission lines at the extreme blue end of submillimeter galaxies' visible spectra. These emission lines are created in extremely hot gas, and they allowed the research team to accurately determine galaxy redshifts for a statistically significant sample of galaxies. The redshifts indicate that the galaxies are so far away that the light we are observing was released when the universe was 20 percent of its current age. This places these galaxies farther away than those seen in images such as the Hubble Deep Field. To be that far away and still observable, submillimeter galaxies must be extremely luminous. Deeply enshrouded in obscuring dust, these galaxies contain at least as many stars as the distant, optically luminous galaxies in the Hubble Deep Field images. The submillimeter galaxies may be the source of all the old stars we see in the universe today. Over the eons, the dust that enshrouded the submillimeter galaxies has been removed as the galaxies themselves have evolved, turning the submillimeter systems of yesterday into today's galaxy population. Share this post Link to post Share on other sites
Capt.Vash 0 Posted September 25, 2003 does that mean that we are seeing something that is what we are? like looking into the past? Share this post Link to post Share on other sites
ARMS 0 Posted September 25, 2003 Older galaxies, mean more time for evolution of life :blink: Share this post Link to post Share on other sites
