A potential runaway supermassive black hole has been identified, traveling at approximately 2.2 million miles per hour (3.6 million km/h) and leaving a trail of young stars extending 200,000 light-years.
Initial Discovery and Observations
The object was initially observed by Pieter van Dokkum's team in 2023 through a faint line in an archival Hubble Space Telescope image. Subsequent observations from the Keck Observatory in Hawaii indicated the black hole has a mass equivalent to 20 million suns. The accompanying trail of young stars stretches 200,000 light-years.
James Webb Space Telescope Confirmation
Further research involved the James Webb Space Telescope (JWST) to detect a bow shock, a signature of the black hole's movement. JWST's mid-infrared instrument captured a clear shockwave at the leading edge of the object, described as a disturbance in hydrogen and oxygen gas. This observation aligned with data from Hubble and Keck, supporting theoretical models.
Research Status
The findings were published on the preprint server Arxiv on December 3 and have been submitted to Astrophysical Journal Letters. The research has not yet undergone peer review.
Implications for Galaxy and Black Hole Evolution
Studying such runaway black holes contributes to understanding galaxy and black hole evolution. Supermassive black holes are typically located at the centers of large galaxies. The ejection of a supermassive black hole from its galaxy is theorized to occur through intense gravitational interactions involving multiple black holes. This specific candidate suggests an interaction between at least two, and possibly three, black holes, each with a mass of at least 10 million suns.
Future Research
Several other candidate runaway black holes exist, though their interpretation remains complex. One such object is the "Cosmic Owl," located approximately 11 billion light-years away, which includes two galactic nuclei and a third supermassive black hole situated within a gas cloud. While some theories suggest this third black hole is a runaway, recent JWST observations by van Dokkum's team propose it may have formed in-situ from gas collapse following a near-collision between the two galaxies.