A new study pinpoints the boundaries of these dark behemoths
Using a new observations technique, a team of astronomers was recently able to image the event horizon of a supermassive black hole in a distant galaxy. This is the first time such data are collected of a boundary that does not even exist in reality.In theory, the event horizon is an area surrounding a black hole that represents a point of no return for all materials falling in. Objects may come close to the dark behemoth but, as long as they don't pass through the event horizon, they can still escape the massive gravitational pull of the black hole.
However, once through this boundary, the forces exerted by the singularity are so intense that they cannot be defeated by others. The event horizon is not clearly marked, but astrophysicists were nevertheless able to image its influences on light.
Since studying a black hole directly is impossible – on account of all light being absorbed by the structure – the team focused its attention on investigating the closest stable orbits they could discover surrounding the object.
Basically, they sought to find the lump of matter (star, planet, asteroid, etc.) that existed in a stable orbit around the supermassive black hole at the core of the galaxy M87. The cosmic formation lies around 50 million light-years away from the Milky Way.
The black hole powering up its core tips the scale at around 6 billion solar masses, far exceeding the mass of our galaxy's black hole, Sagittarius A*. The new investigation was conducted using the Event Horizon Telescope.
“Once objects fall through the event horizon, they're lost forever. It's an exit door from our Universe. You walk through that door, you’re not coming back,” explains the assistant director of the MIT Haystack Observatory, Shep Doeleman.
He is also a research associate at the Smithsonian Astrophysical Observatory. Details of the new study appear in the September 27 issue of the top journal Science, Space reports.
The team learned that the event horizon around M87's supermassive black hole is located around 750 astronomical unit (AU) away from the singularity. That is the equivalent of five times the size of our solar system.
Scientists say that matter may exist closer to the black hole than that, but explain that no objects of large mass could resist the massive gravitational pull for long.