An international research team comprising scientists from the United States, Italy, and other countries has detected, for the first time, the "burping" of a black hole: a supermassive black hole belches roughly every 8.5 days, with the expelled gas originating from its accretion disk. The research team suggests that a smaller black hole continuously traversing the accretion disk of the larger one may be causing these "burps". The related research paper was published on March 27th in the journal "Scientific Reports".
In a distant galaxy, a small black hole is fluttering around like a butterfly within the accretion disk of a larger black hole, causing the larger one to "burp." Image source: MIT website.
This supermassive black hole, weighing in at 50 million times the mass of the Sun, resides at the center of a galaxy located 800 million light-years away from Earth. Research indicates that this black hole emits a large chunk of gas every 8.5 days, then quiets down again. The reason for the "burping" is attributed to a smaller black hole orbiting erratically within its tilted orbit, acting as a "companion" to the larger black hole, periodically kicking gas out of the accretion disk.
The lead author of the study, Dr. Dheeraj Pasham, a scientist at MIT, suggests that the black hole "burps" indicate that accretion disks around black holes might serve as homes to larger cosmic entities, including other black holes and stars. An accretion disk is a super-hot gas disk rotating around a black hole. If their latest models are correct, these "burping" events could reveal much about extreme binary systems.
In December 2020, astronomers first took notice of this supermassive black hole. At that time, the "All-Sky Automated Survey for Supernovae" telescope observed a long-duration outburst from the black hole's accretion disk, increasing the brightness of a small patch of the sky by a factor of 1000. Subsequently, data from X-ray telescopes on the International Space Station enabled scientists to catalog periodic subtle variations in the X-ray data from the supermassive black hole, caused by the black hole's "burping."
After analysis, the research team determined that whenever the smaller black hole crosses the accretion disk of the supermassive black hole, the latter "burps," expelling more material. They also speculate that the supermassive black hole will eventually consume this "companion" in over ten thousand years.
The research team notes that the mass of the smaller black hole ranges from 100 to 10,000 times the mass of the Sun, with a mass difference of 5000 times between the two black holes, making it one of the most extreme mass ratios discovered in binary systems to date. They plan to continue monitoring this system in hopes of detecting more similar systems with the recent deployment of the Laser Interferometer Space Antenna (LISA) by the European Space Agency.
