NASA's NuSTAR 'Bags' its First 10 Supermassive Black Holes

NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) has identified its first 10 supermassive black holes, marking the beginning of what scientists expect will be hundreds of discoveries, according to the space agency.

Equipped with a mast the length of a school bus, NuSTAR is the first telescope capable of focusing the highest-energy X-ray light produced by supermassive black holes into detailed pictures, allowing it to uncover those buried behind thick walls of gas.

"The highest-energy X-rays can pass right through even significant amounts of dust and gas surrounding the active supermassive black holes," said Fiona Harrison, a study co-author and the mission's principal investigator at the California Institute of Technology.

As it was, the most recently discovered supermassive black holes were the result of sheer serendipity: scientists were examining several known targets when they spotted the black holes in the background.

Once identified, the researchers, led by NuSTAR team member David Alexander, went through previous data of the region taken by NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton satellite -- two space telescopes capable of picking up lower-energy X-ray light. In doing so, the scientists found that, while the objects had been previously detected, it took NuSTAR to identify them as something warranting closer inspection.

Through these and other instances of combining observations taken from across the X-ray spectrum, researchers hope to better understand the massive yet largely mysterious space bodies.

"We are getting closer to solving a mystery that began in 1962," Alexander, who works in the physics department at Durham University, said. "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."

Contributing to the study are NASA's Wide-field Infrared Survey Explorer (WISE) and Spitzer missions, which together provide details regarding the mass of the black holes' host galaxies -- information that can then be used to plot trends.

"Our early results show that the more distant supermassive black holes are encased in bigger galaxies," said Daniel Stern, a co-author of the study and the project scientist for NuSTAR at NASA's Jet Propulsion Laborator in Pasadena, Calif. "This is to be expected. Back when the universe was younger, there was a lot more action with bigger galaxies colliding, merging and growing."

Going forward, researchers hope to use NuSTAR to determine, among other things, how many collapsed stars and black holes of different sizes populate the universe.