Peering into the heart of the Milky Way galaxy, NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) has spotted a mysterious glow of high-energy X-rays.These could be the "howls" of dead stars as they feed on stellar companions.
"We can see a completely new component of the centre of our galaxy with NuSTAR's images," said Kerstin Perez from the Columbia University in New York.The centre of our Milky Way galaxy is bustling with young and old stars, smaller black holes and other varieties of stellar corpses -- all swarming around a supermassive black hole called Sagittarius A.NuSTAR, launched into space in 2012, is the first telescope capable of capturing crisp images of this frenzied region in high-energy X-rays.The new images show a region around the supermassive black hole about 40 light-years across.
Astronomers were surprised by the pictures which reveal an unexpected haze of high-energy X-rays dominating the usual stellar activity.When stars die, they don't always go quietly into the night.Unlike stars like our Sun, collapsed dead stars that belong to stellar pairs or binaries can siphon matter from their companions.This zombie-like "feeding" process differs depending on the nature of the normal star, but the result may be an eruption of X-rays.According to scientists, a type of stellar zombie called a pulsar could be at work.Pulsars are the collapsed remains of stars that exploded in supernova blasts.
They can spin extremely fast. As they spin, the beams sweep across the sky, sometimes intercepting the Earth, like lighthouse beacons."We may be witnessing the beacons of a hitherto hidden population of pulsars in the galactic centre," added study co-author Fiona Harrison from the California Institute of Technology.This new result just reminds us that the galactic centre is a bizarre place, the authors concluded.The report appeared in the journal Nature.