The colour scale in the image shows the amount of infrared (heat) radiation coming from warm dust particles in the filaments and luminous stars within a light year of the Galactic centre. The position of the black hole is indicated by an asterisk. The lines trace the magnetic field directions and reveal the complex interactions between the stars and the dusty filaments, and the impact that they and the gravitational force has on them. The observations were made with the largest telescope in Europe, which allowed details of the fine structure in the magnetic fields to be revealed for the first time. Credit: E. Lopez-Rodriguez / NASA Ames / University of Texas at San Antonio
Using a sophisticated camera, astronomers have mapped out the substances in the supermassive black hole at the center of the Milky Way.
A team from the University of Oxford has revealed a new high-resolution map of the magnetic field lines in gas and dust swirling around the supermassive black hole at the center of the Milky Way, using a CanariCam infrared camera attached to the Gran Telesclines Canarias on the island of La Palma.
“Big telescopes like GTC, and instruments like CanariCam, deliver real results,” Pat Roche, a professor from the University of Oxford, said in a statement. “We’re now able to watch material race around a black hole 25,000 light years away, and for the first time see magnetic fields there in detail.”
The new map covers a region about one light year on each side of the supermassive black hole and shows the intensity of infrared light.
The map also traces magnetic field lines within filaments of warm dust grains and hot gas, which appear as thin lines reminiscent of brush strokes in a painting.
Black holes are objects with gravitational fields strong enough to keep light from escaping. The center of almost every galaxy appears to host a black hole.
Stars move around the black hole at the center of the Milky Way at speeds up to 30 million kilometers an hour, indicating that it has a mass of more than a million times of the Sun.
Visible light from sources in the center of the Milky Way is blocked by clouds of gas and dust. Infrared light, along with X-rays and radio waves, pass through the black holes, allowing astronomers use to see the region more clearly.
CanariCam combines infrared imaging with a polarizing device that preferentially filters light with the particular characteristics associated with magnetic fields.
The filaments are several light years long and appear to meet close to the black hole at a point below center on the map. This could indicate where orbits of steams of gas and dust meet. Despite strong winds flowing from the bright stars in the center of the Milky Way, the filaments remain in place, bound by the magnetic fields within them.
The magnetic field is less clearly aligned with the filaments elsewhere within the supermassive black hole and depending on how the material flows, some of it may eventually be captured and engulfed by the black hole.
While the origin of the magnetic fields in the black hole are not understood, the new map gives astronomers more detailed information on the relationship between the bright stars and the dusty filaments.
The researchers believe it is likely that a smaller magnetic field is stretched out as the filaments are elongated by the gravitational influence of the black hole and stars in the galactic center.
The team will now use CanariCam to probe magnetic fields in dusty regions in the Milky Way.
