At the center of our galaxy is a supermassive black hole roughly four million times heavier than our Sun. Despite its size, we do not know much about the black hole, but a recent discovery is helping to uncover its secrets. A team led by researchers at the Max Planck Institute for Radio Astronomy, that includes researchers at the National Radio Astronomy Observatory, is studying the light from a magnetar to measure the magnetic field of matter near the black hole.
Magnetars are a special class of pulsars, themselves a class of neutron stars characterized by rapid spinning that causes intense light to escape from their poles, making them appear to pulse. Magnetars are pulsars with extremely strong magnetic fields, with the recently discovered one having a field 100 trillion times stronger than Earth's. At just half a light year from the supermassive black hole, it is the closest pulsar to it, and importantly the accretion disk that orbits the black hole as well. Black holes and their accretion disks have a strong relationship that we can use to learn about one by studying the other. In this case we are analyzing the light emitted by the magnetar being rotated as it passes through the disk, allowing us to probe its magnetic field.
The magnetic field of an accretion disk and its host black hole is very important as it affects the black hole's feeding behavior, by potentially creating jets that throw matter away from the black hole. Thanks to this magnetar, we are finally able to study the magnetic field of our supermassive black hole's accretion disk.