NASA researchers have identified an unusual case of a black hole in the galaxy NGC 5084, which appears to be rotating in an unexpected direction. This finding emerged from a re-evaluation of archival data using new image analysis techniques developed at NASA's Ames Research Center.
The analysis revealed four long plumes of plasma, or hot, charged gas, extending from NGC 5084. One pair of plumes rises above and below the galaxy's plane, while a second pair forms an 'X' shape within the galaxy itself. Such multiple plumes are rare, as galaxies typically exhibit only one or two.
The innovative method, spearheaded by Ames scientist Alejandro Serrano Borlaff, was designed to detect low-brightness X-ray emissions from the Chandra X-ray Observatory. The peculiar findings prompted further investigation, leading to additional observations from other telescopes, including NASA's Hubble Space Telescope and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.
Subsequent analyses unveiled a dusty inner disk orbiting the galaxy's center, which rotates at a 90-degree angle to the galaxy's overall rotation, indicating the presence of a supermassive black hole. This unique orientation suggests significant changes in the galaxy's structure over time.
According to Borlaff, the combination of different observational techniques allowed for a comprehensive view of NGC 5084's history. Astrophysicist Pamela Marcum noted that the dual X-ray plumes and the unusual disk structure provide valuable insights into the galaxy's past.
Potential explanations for the galaxy's atypical features include past collisions with other galaxies or the formation of a chimney of superheated gas. Further studies are needed to elucidate the events that led to the current state of NGC 5084.
This research was published on December 18 in The Astrophysical Journal, detailing the Selective Amplification of Ultra Noisy Astronomical Signal (SAUNAS) method, which enhances the detection of faint astronomical signals.