Domain: sciforums.com
Stories and comments across the archive that link to sciforums.com.
Stories · 2
-
White Dwarfs Could be Dark Matter
Porfiry writes "An international team of astronomers has detected what could be a significant portion of the galactic dark matter that has eluded astronomers for nearly 70 years. Scanning digitized images of the southern sky, the team found 38 previously unseen cool white dwarfs within about 450 light years of Earth. If the density of these newly discovered white dwarfs is indicative of the rest of the galaxy's halo, these dead stars would comprise at least three percent of the dark matter of the halo, and perhaps as much as 35 percent." -
Universe Teeming With Black Holes
Porfiry writes "For the first time, astronomers believe they have proof black holes of all sizes once ruled the universe. NASA's Chandra X-ray Observatory provided the deepest X-ray images ever recorded (a million-second exposure), and those pictures deliver a novel look at the past 12 billion years of black holes. Combining infrared and X-ray observations, the Penn State team found veils of dust and gas are common around young black holes. 'The discovery of this object, some 12 billion light years away, is key to understanding how dense clouds of gas form galaxies, with massive black holes at their centers,' said Colin Norman of Johns Hopkins University."