Astronomers capture shadow of dust disc around supermassive black hole

A cosmic display of light and shadow could be generated by a supermassive black hole at the centre of a galaxy and the dusty disc surrounding it.

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Published: November 21, 2020 at 8:10 am

Cone-shaped shadows emanating from the bright centre of galaxy IC 5063 could be cast by the dusty ring surrounding the supermassive black hole at its centre. Credit: NASA, ESA, STScI and W.P. Maksym (CfA)
Cone-shaped shadows emanating from the bright centre of galaxy IC 5063 could be cast by the dusty ring surrounding the supermassive black hole at its centre. Credit: NASA, ESA, STScI and W.P. Maksym (CfA)

Astronomers using the Hubble Space Telescope may have captured an image of shadows cast by a dusty ring surrounding a supermassive black hole at the centre of a galaxy.

An image released by the team shows the centre of nearby active galaxy IC 5063, where bright rays of light and dark shadows are seen emanating from within.

In particular, a two-pronged shadow appears to be emerging from the bright galactic centre - seen below and above the galaxy in the image - that could be cast by the dust ring.

The astronomers behind the study are led by Peter Maksym of the Center for Astrophysics at Harvard & Smithsonian in the US.

Studying the galaxy, the team have managed to trace the projection of light rays back into the galactic core, where resides a supermassive black hole.

Discover more:

An artist's impression of the dusty disc surrounding the black hole at the centre of galaxy IC 5063. The disc is casting its shadows into space, while bright rays pass through gaps in the material. Credit: NASA, ESA, and Z. Levy (STScI)
An artist's impression of the dusty disc surrounding the black hole at the centre of galaxy IC 5063. The disc is casting shadows into space, while bright rays pass through gaps in the material. Credit: NASA, ESA, and Z. Levy (STScI)

Black holes are dense regions of space from which not even light can escape, and astronomers infer that most galaxies, including our own Milky Way, have a supermassive black hole at their centre (although we don't yet definitively know where the nearest black hole to Earth is.

IC 5063 is no exception, and like other galaxies its supermassive black hole can be detected as streams of light energy generated as cosmic matter falls inwards.

But what can also be seen in this new Hubble image are displays of shadows and light stretching across at least 36,000 lightyears. The team believe these could be cast by a ring of dusty material surrounding the black hole.

Sunlight filters through clouds creating crepuscular rays, also known as 'God rays', in this image captured at Grand Tetons National Park in the US in 2017. Similar effects could be occurring at galaxy IC 5063 where light is partially blocked by the dusty disc surrounding the supermassive black hole at its centre. Credit: Z. Levay The photographer was facing east—away from the iconic Grand Teton Mountains—when he snapped this image in 2017. The light rays are formed by sunlight piercing the clouds. The darker regions represent the clouds casting shadows where sunlight could not pass through. This interplay of light and shadow is similar to the bright rays and dark shadows stretching across the nearby active galaxy IC 5063. In that case, a monster black hole in the galaxy’s core is producing a gusher of light from superheated infalling gas. Most of the light is penetrating the dust ring encircling the black hole, creating the bright rays. However, some light hits dense patches in the ring, casting the ring’s shadow into space.
Sunlight filters through clouds creating crepuscular rays in this image captured at Grand Tetons National Park, US in 2017. Similar effects could be occurring at galaxy IC 5063 where light is partially blocked by a dusty disc surrounding the supermassive black hole at its centre. Credit: Z. Levay

This dusty disc only blocks some of the light, however, allowing rays of light to beam outwards, generating dark cone-shaped rays similar to those that can be seen on Earth as sunlight passes through gaps in clouds (see image above).

"It's a really cool effect that I don't think we've seen before in images, although it has been hypothesised," says Maksym.

"Scientifically, it's showing us something that is hard - usually impossible - to see directly. We know this phenomenon should happen, but in this case, we can see the effects throughout the galaxy.

"Knowing more about the geometry of the torus will have implications for anybody trying to understand the behaviour of supermassive black holes and their environments."

Image stats

  • Observatory Hubble Space Telescope
  • Release date 19 November 2020
  • Image credit NASA, ESA, STScI and W.P. Maksym (CfA)

Read more about this story via the Hubble Space Telescope website.

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