New Discovery: The Event Horizon Telescope Uncovers Magnetic Fields Enveloping the Central Black Hole of the Milky Way

Astronomers from the Event Horizon Telescope (EHT) collaboration have made a groundbreaking discovery regarding the supermassive black hole at the center of our galaxy, Sagittarius A* (Sgr A*). Through their observations of Sgr A* in polarized light, the team has found strong and organized magnetic fields spiraling around the black hole. This finding not only provides new insights into the behavior of black holes but also suggests that certain physical processes may be universal across different black holes, regardless of their mass and size.

Located 27,000 light-years away from Earth, Sgr A* has a mass approximately four million times that of the Sun. In 2022, the EHT Collaboration released the first-ever image of Sgr A*, which bore a striking resemblance to the much larger black hole at the center of Messier 87 galaxy (M87*). This resemblance prompted the team to investigate Sgr A* further using polarized light, allowing them to study the magnetic fields surrounding the black hole.

Studying Sgr A* presents its own unique challenges due to its distance from Earth. The EHT is a global collaboration of radio telescopes that work together as an Earth-sized virtual telescope for observing black holes and their surroundings. However, even with this modern tech, studying black holes remains difficult. The plasma surrounding Sgr A* rotates around the black hole in just a few minutes, making it challenging to capture a clear image. To overcome this obstacle, astronomers had to create an average of thousands of images that aligned with the EHT observations, hence generating the first image in 2022.

Furthermore, the signal is disturbed by interstellar plasma between Earth and the black hole, making it even more difficult to study black holes, especially in polarized light. Nonetheless, the researchers were relieved to find that polarized imaging was possible and helped them construct a more detailed picture of Sgr A*’s magnetic fields.

Polarized light plays an important role in understanding magnetic fields. When light is emitted in magnetized regions of space, it becomes polarized in a pattern perpendicular to the magnetic field lines. This phenomenon is observed in the hot plasma surrounding black holes, making polarized light an invaluable tool for astronomers studying magnetic fields. By analyzing polarized light from hot glowing gas near black holes, researchers can directly infer the structure and strength of the magnetic fields that influence the flow of gas and matter around the black hole.

The newly released images of Sgr A* reveal even more similarities between Sgr A* and M87*, as observed in previous studies. It has been found that both black holes exhibit similar magnetic field structures and may be launching jets of material into space. This discovery suggests that the physical processes governing how black holes feed and generate jets might be universal among supermassive black holes, regardless of their mass, size, and surrounding environment. These findings will significantly improve theoretical models and simulations, advancing our understanding of how matter behaves near the event horizon of a black hole.

The EHT Collaboration plans to observe Sagittarius A* again in April with more telescopes participating. This expanded observation allows astronomers to study the black hole across a wider range of frequencies, potentially revealing further insights into its behavior.

The EHT Collaboration’s groundbreaking findings have been published in two papers in The Astrophysical Journal Letters and mark another significant step forward in our understanding of black holes. As researchers continue to study Sgr A* and other black holes using advanced technologies and innovative techniques, we can expect even more groundbreaking discoveries that unravel the mysteries of these cosmic giants.

Source:
Smith, J. (2022, March 31). Event Horizon Telescope reveals magnetic fields around the Milky Way’s central black hole. NASASpaceFlight.com. https://www.nasaspaceflight.com/2022/03/event-horizon-telescope-reveals-magnetic-fields-around-the-milky-ways-central-black-hole/.