okt 022012
 
The Case of the Missing Quasar Gas Clouds

  The case of the missing quasar gas clouds has been solved by a worldwide research team led by Penn State University astronomers Nurten Filiz Ak and Niel Brandt. The the answer is: blowin’ in the wind. This discovery is being announced today in a paper published in The Astrophysical Journal, which describes 19 distant quasars [continue reading]

aug 032012
 
The Awakening of a Distant Galaxy's Dormant Black Hole

  Last year, astronomers discovered a quiescent supermassive black hole in a distant galaxy that erupted after shredding and consuming a passing star. Now researchers have identified a distinctive X-ray signal observed in the days following the outburst that comes from matter on the verge of falling into the black hole.  This illustration highlights the [continue reading]

jul 182012
 
Astronomers Explain Earth's Lack of Water

  With large swaths of oceans, rivers that snake for hundreds of miles, and behemoth glaciers near the north and south poles, Earth doesn’t seem to have a water shortage. And yet, less than one percent of our planet’s mass is locked up in water, and even that may have been delivered by asteroids after [continue reading]

jun 012012
 
Light 'Echo' Around Supermassive Black Hole

  Astronomers studying the galaxy NGC 4151 with ESA’s XMM-Newton space observatory have detected X-rays emitted and then reflected by ionised iron atoms very close to the supermassive black hole hosted at the galaxy’s core. By measuring the time delays occurring in these ‘reverberation’ events, they were able to map the vicinity of this black [continue reading]

mei 302012
 
The Milky Way's Central Black Hole Used To Be Active

  As galaxies go, our Milky Way is pretty quiet. Active galaxies have cores that glow brightly, powered by supermassive black holes swallowing material, and often spit twin jets in opposite directions. In contrast, the Milky Way’s center shows little activity. But it wasn’t always so peaceful. New evidence of ghostly gamma-ray beams suggests that [continue reading]