Orbiting supermassive black holes are real, and this is a big deal

28 Jun 2017

Artist’s conception of two orbiting supermassive black holes. Image: Joshua Valenzuela/UNM

For the first time, astronomers have proven that supermassive black holes that orbit galaxies exist, and this could help tell us how galaxies form.

In the field of astronomy, it appears that a trickle soon turns into a flood, as evidenced by the first detection of a gravitational wave in 2015.

Since then, the confirmation of Einstein’s century-old theory has helped to solve a number of cosmic mysteries surrounding galaxies and the formation of black holes.

Future Human

Now, for the first time ever, researchers at the University of New Mexico have observed and measured the orbital motion between two supermassive black holes.

Despite putting in decades of research into the little-understood phenomenon, it was not until the gravitational wave discovery that things began to fall into place. This is because the collision between the black holes that created the wave helps us to understand what leads up to their merger.

In the research published to The Astrophysical Journal, Karishma Bansal and Prof Greg Taylor used a system of 10 radio telescopes to observe a pair of supermassive black holes, located approximately 750m light years from Earth in Galaxy 0402+379.

Despite the huge distance, it is actually perfect for observation here on Earth. Over a period of time, the researchers tracked the trajectories and, to their astonishment, the black holes were confirmed to be orbiting one another.

15bn times the mass of our sun

The supermassive black holes in question have a combined mass of about 15bn times that of our sun, with an orbital period of around 24,000 years.

Over the course of its observation, the team has yet to see even the slightest curvature in orbit.

“If you imagine a snail on the recently discovered Earth-like planet orbiting Proxima Centauri – 4.243 light years away – moving at 1cm a second, that’s the angular motion we’re resolving here,” said Roger W Romani, professor of physics at Stanford University and member of the research team.

By continuing to observe the orbit and interaction of these two supermassive black holes, science will gain a better understanding of what the future of our own galaxy might look like.

Taylor added: “Supermassive black holes have a lot of influence on the stars around them and the growth and evolution of the galaxy.

“So, understanding more about them and what happens when they merge with one another could be important for our understanding for the universe.”

Colm Gorey was a senior journalist with Silicon Republic