A NASA Hubble image may show the first runaway supermassive black hole ever discovered.
A trail indicating an object traveling away from a galaxy suggests that a black hole has been ejected.
A rogue black hole may have generated a shock wave that made a trail of new stars visible in the image.
The Hubble Space Telescope is still making first-of-its-kind discoveries after more than three decades in space. Its latest? Observations of the first ever supermassive black hole to disappear from its own galaxy.
That’s what a team of astronomers suggests in a new study posted online. The study has been peer reviewed for publication in the Astrophysical Journal Letters, according to Pieter van Dokkum, an astrophysicist at Yale University who led the new study.
Even experts not involved in the study are excited by the team’s findings.
“The observations all fit this scenario,” Manuela Campanelli, an astrophysicist at the Rochester Institute of Technology who is not involved in the study but has simulated runaway black holes in her research, told Insider.
The first possible photo of a ‘rogue state’ supermassive black hole
What you see above are two pictures of the same thing that tell the story of what happened.
Look at the zoomed-in image on the right: The large spot in the upper right is a galaxy. Then follow the faint line that follows away from it, ending in a dot in the lower left. That’s where scientists think the runaway black hole is hiding.
Black holes are inherently invisible. The reason astronomers are able to “see” any black hole is because it is surrounded by a swirling hot disk of gas, stars, and other cosmic stuff that is visible.
But the most fascinating part of these images is the streak you see trailing behind the black hole. That’s what caught the eyes of the researchers when they were examining nearby stars.
They believe that the long tail emerging from the black hole is actually a trail of newborn stars that formed after the black hole was ejected from its home galaxy and ripped through space, generating a shock wave that caused clouds of intergalactic gas to collapse into stars.
“I thought I had actually made a mistake that there was this strange streak in the picture,” van Dokkum told Insider. “It didn’t look like any astrophysical objects at first. And then it turned out it was real. It was in other data sets, too. And that’s when I got excited.”
Although black holes are notorious for consuming and destroying stars, this one appears to be creating them as well.
Further observations, likely with the James Webb Space Telescope, are needed to confirm that the object in the image is indeed a runaway supermassive black hole.
Why a supermassive black hole would go rogue
Supermassive black holes are amazingly dense objects with the mass of billions of suns, and scientists believe there is one at the center of every galaxy. Needless to say, it would take a lot of force to kick one out of one’s home.
One such catastrophic event that could possibly do the job is if two galaxies collide and their central black holes merge. A collision between black holes is one of the most violent, violent events in the universe, and it can send a smaller remnant black hole erupting into the void.
Astrophysicists have long theorized that black holes could “sling” or “run away” if other black holes pushed them out of their galaxies.
But no one has ever confirmed a black hole wandering through intergalactic space, much less one super massive black hole goes rogue.
And while two galaxies colliding is the simplest explanation for a rogue black hole, that’s not what appears to have happened here.
2 other black holes may have ejected this one in a rare, violent event
Van Dokkum believes that this black hole had a particularly rare, dramatic, violent exit. Here’s his theory: Two galaxies merged and their supermassive black holes collapsed due to their gravity.
It happens all the time. Hubble has photographed plenty of merging galaxies, like the ones pictured below. The next step is what made this merger so strange.
The team believes that a third galaxy arrived with a third black hole, and its gravity caused a complex dance of the three black holes, which ended up hurling one of them into the distance.
Ever since then, over a period of 39 million years, the runaway black hole has been screaming away from its home galaxy at a speed of about 1,600 kilometers (almost 1,000 miles) per second, according to van Dokkum’s team’s calculations. For reference, at that speed it would take you 25 seconds to circle the entire Earth.
Basically, this supermassive black hole (if that’s what it is) got third-wheeled and kicked out of its own home. Evidence for this third galaxy has yet to be confirmed, but the team is investigating a trail they see on the opposite side of the galaxy where they believe the other two black holes merged and were then ejected by the recoil.
“The picture really tells the story,” said van Dokkum.
That makes this event exceptionally rare, Campanelli said, because it involved three black holes instead of the conventional two that theorists typically posit in a scenario like this.
Follow the trail of newborn stars – if it’s not just a jet plane
The other explanation for the mysterious trail in van Dokkum’s Hubble photo is a fairly common one: jets of material shooting out from the centers of galaxies with highly active black holes.
But van Dokkum and Campanelli both say that’s unlikely, based on the shape of the path in the new image. Jets shooting from galactic centers fan away from the galaxy, while material shoots from a point and spreads out into the distance, like the one shown in the Hubble image below:
Instead, the trail in van Dokkum’s Hubble image fans out against the galaxy. It appears to be a trail of new stars that formed when the wandering black hole generated shock waves in the intergalactic gas.
Campanelli added that the compact and irregular shape of the galaxy is “typical” of galaxies formed by mergers.
“If it turns out not to be real, I will be surprised,” van Dokkum said. “If it’s not real, I think it’s actually a combination of a couple of other gas clouds or something that seemed to stand in such a way that it looks like a streak.”
Although they are invisible, there is no need to worry about rogue states, supermassive black holes that sneak up on us from other galaxies.
“We would have seen the effects of it if it was near us,” van Dokkum said.
Read the original article on Business Insider