Revealing hidden black holes with NASA's NuSTAR 'x-ray eyes'

NASA's NuSTAR uses high-energy X-rays to search for hidden supermassive black holes. NASA's Jet Propulsion Laboratory explains.

Transcript

00:00Most black holes in the universe are hiding.

00:03So how do we find these big, hungry cosmic beasts?

00:06Here's a clue, a space telescope with X-ray vision.

00:15Black holes are one of the biggest mysteries of the cosmos.

00:18With gravity so intense, nothing can escape, not even light.

00:23The smallest black holes we know of form when big stars run out of fuel and collapse.

00:29Then there are the supermassive black holes.

00:31Scientists don't currently know where they come from,

00:34but we do know they have up to tens of billions of times the mass of the Sun.

00:39Scientists think every large galaxy in the universe

00:42has a supermassive black hole at its centre.

00:45But what role do they play in how galaxies grow and change?

00:50There are several ways to look for supermassive black holes.

00:53We can observe the way stars orbit around them.

00:56This is how scientists identified the supermassive black hole at the centre of our own galaxy,

01:01the Milky Way.

01:03We can spot the powerful jets of hot plasma that are ejected as they feed.

01:08We can detect the ripples in space-time that occur as they merge.

01:13We can even detect the radiation emitted when stars travel too close and get torn apart.

01:17We can also spot the glowing disks of gas and dust that orbit black holes,

01:23which can sometimes resemble the approximate shape of a doughnut.

01:27If the doughnut is face-on, we can see the bright disk at the centre.

01:31But there's a problem.

01:33Most are only showing us their edge, and the bright disk is obscured by the wall of this doughnut.

01:39That's where New Star comes in.

01:41The space telescope has powerful X-ray vision

01:43that can see certain objects or features of the universe that are invisible to the human eye.

01:49The high-energy X-rays can also penetrate thick gas and dust.

01:54Recently, we combined 10 years of New Star data

01:58with measurements from other missions to sample the sky at X-ray wavelengths.

02:02We now measure that at least 35% of the growing supermassive black holes in the universe are hidden.

02:09It's important that we find and study supermassive black holes

02:13because they can teach us a lot about how galaxies grow and evolve.

02:18For example, black holes slow down star formation.

02:21If we didn't have a supermassive black hole in our own Milky Way,

02:25we would expect to have many more stars in the sky.