Strong magnetic fields at the edge of the Milky Way's central black hole

ENGINEERINGNET.BE – Previous examination of light around the black hole in M87 showed that surrounding magnetic fields allowed this black hole to shoot powerful jets of matter into space. New images show that the same may also be true for Sagittarius A*.

“We see that strong, entangled and organized magnetic fields exist in the vicinity of the black hole at the center of the Milky Way,” says EHT's Sarah Isson. “These types of fields are crucial to the way black holes interact with the gas and matter in their environment.”

“By imaging polarized light from glowing hot gas near black holes, we can infer the structure and strength of the magnetic fields that accompany the flow of gas and matter that feed and extrude the black hole,” says project coordinator Angelo Ricarte.

To observe Sagittarius A*, the EHT team linked eight telescopes around the world to create a mock Earth-sized telescope.

The Atacama Large Millimeter/submillimeter Array (ALMA), of which the European Southern Observatory (ESO) is a partner, and the Atacama Pathfinder Experiment (APEX) hosted by ESO, both in northern Chile, were part of the network that made the observations. Performed in 2017.

“As the largest and most powerful telescope in the EHT, ALMA played a key role in capturing this image,” said Maria Díaz Trejo, ESO's European ALMA program scientist.

“ALMA will soon undergo an ‘extreme revamp’, a broadband sensitivity upgrade, which will make it even more sensitive and will continue to play an essential role in future EHT observations of Sagittarius A* and other black holes.”

The EHT has made several observations since 2017 and will observe Sagittarius A* again in April 2024. As new telescopes are added, bandwidth is increased, and new observing frequencies are added, the images will improve.

Expansions planned over the next decade will allow the production of high-resolution movies of this black hole, showing its hidden flow, and will allow astronomers to observe similar polarization signatures in other black holes.

Meanwhile, if the EHT could be extended out into space, it would provide sharper images of black holes than ever before.