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Lee esta historia en espa\u00f1ol\u00a0aqu\u00ed<\/strong><\/em>.<\/p>\n NASA researchers have discovered a perplexing case of a black hole that appears to be \u201ctipped over,\u201d rotating in an unexpected direction relative to the galaxy surrounding it. That galaxy, called NGC 5084, has been known for years, but the sideways secret of its central black hole lay hidden in old data archives. The discovery was made possible by new image analysis techniques developed at NASA\u2019s Ames Research Center in California\u2019s Silicon Valley to take a fresh look at archival data from the agency\u2019s Chandra X-ray Observatory.<\/p>\n Using the new methods, astronomers at Ames unexpectedly found four long plumes of plasma \u2013 hot, charged gas \u2013 emanating from NGC 5084. One pair of plumes extends above and below the plane of the galaxy. A surprising second pair, forming an \u201cX\u201d shape with the first, lies in the galaxy plane itself. Hot gas plumes are not often spotted in galaxies, and typically only one or two are present.<\/p>\n The method revealing such unexpected characteristics for galaxy NGC 5084 was developed by Ames research scientist Alejandro Serrano Borlaff and colleagues to detect low-brightness X-ray emissions in data from the world\u2019s most powerful X-ray telescope. What they saw in the Chandra data seemed so strange that they immediately looked to confirm it, digging into the data archives of other telescopes and requesting new observations from two powerful ground-based observatories.<\/p>\n The surprising second set of plumes was a strong clue this galaxy housed a supermassive black hole, but there could have been other explanations. Archived data from NASA\u2019s Hubble Space Telescope and the Atacama Large Millimeter\/submillimeter Array (ALMA) in Chile then revealed another quirk of NGC 5084: a small, dusty, inner disk turning about the center of the galaxy. This, too, suggested the presence of a black hole there, and, surprisingly, it rotates at a 90-degree angle to the rotation of the galaxy overall; the disk and black hole are, in a sense, lying on their sides.<\/p>\n The follow-up analyses of NGC 5084 allowed the researchers to examine the same galaxy using a broad swath of the electromagnetic spectrum \u2013 from visible light, seen by Hubble, to longer wavelengths observed by ALMA and the Expanded Very Large Array of the National Radio Astronomy Observatory near Socorro, New Mexico.<\/p>\n \u201cIt was like seeing a crime scene with multiple types of light,\u201d said Borlaff, who is also the first author on the paper reporting the discovery. \u201cPutting all the pictures together revealed that NGC 5084 has changed a lot in its recent past.\u201d<\/p>\n Alejandro Serrano Borlaff<\/p>\n NASA Research Scientist<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n \u201cDetecting two pairs of X-ray plumes in one galaxy is exceptional,\u201d added Pamela Marcum, an astrophysicist at Ames and co-author on the discovery. \u201cThe combination of their unusual, cross-shaped structure and the \u2018tipped-over,\u2019 dusty disk gives us unique insights into this galaxy\u2019s history.\u201d<\/p>\n Typically, astronomers expect the X-ray energy emitted from large galaxies to be distributed evenly in a generally sphere-like shape. When it\u2019s not, such as when concentrated into a set of X-ray plumes, they know a major event has, at some point, disturbed the galaxy.<\/p>\n Possible dramatic moments in its history that could explain NGC 5084\u2019s toppled black hole and double set of plumes include a collision with another galaxy and the formation of a chimney of superheated gas breaking out of the top and bottom of the galactic plane.<\/p>\n More studies will be needed to determine what event or events led to the current strange structure of this galaxy. But it is already clear that the never-before-seen architecture of NGC 5084 was only discovered thanks to archival data \u2013 some almost three decades old \u2013 combined with novel analysis techniques.<\/p>\n The paper presenting this research was published Dec. 18 in The Astrophysical Journal. The image analysis method developed by the team \u2013 called Selective Amplification of Ultra Noisy Astronomical Signal, or SAUNAS \u2013 was described in The Astrophysical Journal in May 2024.<\/p>\n