In the world of astronomy, black holes are known for their elusive nature and mysterious properties. While many focus on the event horizon, the true essence of a black hole lies in its accretion disc. This disc is a swirling mass of hot gas and dust that surrounds the black hole.
Albert Einstein’s theory of general relativity states that the space around a rotating object, including black holes, becomes distorted. This phenomenon, known as “frame dragging,” is particularly pronounced in rapidly rotating black holes. As gas and dust fall into the black hole, they form an accretion disc that lies within its equatorial plane. These discs possess the ability to generate powerful magnetic fields, emit intense x-rays, and even produce gas jets that race away from the black hole at nearly the speed of light.
Despite our knowledge of accretion discs, scientists have long struggled to fully comprehend their dynamics and accurately measure their size. Their calculations were previously based on the fluctuations in the brightness of quasars. However, a recent breakthrough enabled scientists to precisely measure the size of an accretion disc surrounding a supermassive black hole.
In a groundbreaking study, a team of astronomers deployed a new technique to study the emission lines of a supermassive black hole at the center of the III ZW 002 galaxy. By observing the double peaks in the hydrogen and oxygen spectra using the Gemini North telescope, the researchers were able to determine the rotational motion of the accretion disc.
Utilizing these observations, the scientific team deduced that the accretion disc has a size of approximately 40 light days. This measurement marks a significant milestone in our understanding of black holes and their intricate relationship with the accretion discs that encompass them.