Astronomers this week announced that NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) has spotted its first 10 supermassive black holes. NuSTAR, an X-ray space telescope, was launched in June 2012 on a mission to conduct surveys for supermassive black holes (those billions of times more massive than our sun) and supernova remnants. A new paper, published in the Astrophysical Journal, describes how these first black holes were found by accident, in images taken of other likely black hole candidates.
"We found the black holes serendipitously," said David Alexander lead author of the paper and an astronomer at Durham University. "We were looking at known targets and spotted the black holes in the background of the images."
These black holes are the first of what astronomers hope are hundreds to be found by NuSTAR in the coming years. The telescope is able to pick up the high-energy X-ray light that are given off by galaxies containing supermassive black holes. Finding these objects will help researchers determine several questions, such as how many supermassive black holes there are in the universe, and whether they may be the source of the observed cosmic X-ray background.
"We are getting closer to solving a mystery that began in 1962," said Alexander. "Back then, astronomers had noted a diffuse X-ray glow in the background of our sky but were unsure of its origin. Now, we know that distant supermassive black holes are sources of this light, but we need NuSTAR to help further detect and understand the black hole populations."
(Image courtesy NASA/JPL-Caltech)