Nasa researchers have identified a black hole in galaxy NGC 5084 rotating at an unexpected angle, tipped over relative to its surrounding galaxy.
This discovery was made possible through a new image analysis method called Selective Amplification of Ultra Noisy Astronomical Signal (SAUNAS). The findings were published in The Astrophysical Journal on Wednesday.
This unusual orientation was discovered using advanced image analysis methods created at Nasa’s Ames Research Center.
Galaxy NGC 5084
Galaxy NGC 5084 has been studied for years, but its oddly aligned black hole was hidden in old data. Using information from Nasa’s Chandra X-ray Observatory, researchers found four plumes of hot, charged gas coming from the galaxy. One pair stretched vertically above and below the galaxy, while the second pair formed an “X” shape within the galaxy’s plane. Such structures are rare, as most galaxies have only one or two plumes.
Alejandro Serrano Borlaff, the Ames research scientist behind the new analysis method, explained: “It was like seeing a crime scene with multiple types of light. Putting all the pictures together revealed that NGC 5084 has changed a lot in its recent past,” he said in a statement.
‘Tipped-over’ disk
The discovery led researchers to study NGC 5084 further using data from Nasa’s Hubble Space Telescope, ALMA in Chile, and the National Radio Astronomy Observatory in New Mexico. They found a dusty inner disk orbiting the galaxy’s core at a 90-degree angle to the galaxy’s rotation. The disk and black hole seemed tilted on their sides.
“Detecting two pairs of X-ray plumes in one galaxy is exceptional,” said Pamela Marcum, an Ames astrophysicist, as quoted by Nasa. “The combination of their unusual, cross-shaped structure and the ‘tipped-over,’ dusty disk gives us unique insights into this galaxy’s history.”
Researchers think NGC 5084’s unusual structure might be due to major cosmic events, like a galaxy collision or superheated gas chimneys breaking through the galactic plane.