They discover a huge supermassive black hole roaming the cosmosCredits: NASA, ESA, Leah Hustak (STScI).
Related Astronomers have discovered a “runaway” supermassive black hole, potentially the first observational evidence that supermassive black holes can be ejected from their host galaxies. It is an invisible monster loose in space, crossing the cosmos uncontrollably and at extreme speed: it weighs up to 20 million suns and leaves behind a “trail” of newborn stars 200,000 light-years long never seen before. which is equivalent to twice the diameter of our galaxy, the Milky Way. Accidentally captured by NASA’s Hubble Space Telescope, a mysterious roaming black hole intrigues astronomers. According to a new study, recently published in The Astrophysical Journal Letters, the gigantic structure that travels through the cosmos would be the first supermassive black hole ejected from its galaxy that has been identified to this day. A unique detail is that it leaves behind a trail of young stars as its journey unfolds, in a phenomenon never before appreciated.
New stars in its wake Follow-up spectroscopic observations revealed that the “wake” left behind by the runaway supermassive black hole is composed of a string of newborn blue stars, reaching 200,000 light-years long. After being ejected from its home galaxy, the black hole compressed gas on its way to leave behind a long trail of young stars: this unusual event occurred when the Universe was about half its current age, or about 6.9 billion years old. years. years. Scientists believe that the gas associated with the Blue Star Trail is being impacted and heated by the motion of a supermassive black hole or, failing that, could be radiation from an accretion disk around the rogue structure. “The gas in front of the black hole is discharged by this very high speed supersonic impact. It is not yet known exactly how it works: it is unlike anything we have seen before,” said NASA scientist Pieter van Dokkum, a specialist at Yale University in New Haven, United States, and lead author, in a press release. of the new study.
An extreme and unique event Everything indicates that this true “intergalactic rocket” is the result of multiple collisions of supermassive black holes. Astronomers suspect that two galaxies originally merged approximately 50 million years ago, resulting in the formation of a supermassive black hole binary system at their center. Subsequently, another galaxy with its own supermassive black hole would have collided with the previous structure. This caused one of the supermassive black holes, precisely our “runaway voyager”, to shoot out into the cosmos in a specific direction. At the same time, the binary black holes escaped in the opposite direction, due to the forces involved in the collision. The ejected supermassive black hole, with a mass of about 20 million suns, is traveling at extreme speed on a gas “highway” that spawns new stars in its path: it is traversing the cosmos at a speed that would allow it to travel from Earth to the Moon in just 14 minutes. Now, scientists will make follow-up observations with the James Webb Space Telescope and the Chandra X-ray Observatory, to finally confirm the explanation for the origin and nature of the rogue black hole.
Source: A runaway supermassive black hole candidate identified by shocks and star formation in its wake. Pieter van Dokkum et al. The Astrophysical Journal Letters (2023). DOI: https://doi.org/10.3847/2041-8213/acba86