New Image of Supermassive Black Hole Reveals Swirling Magnetic Fields
Black holes push our understanding of physics to the very edge. There are plenty of theories about how the universe works near the event horizon of these massive collapsed stars, and the Event Horizon Telescope (EHT) project could tell us which ones are right. The EHT gave us the iconic 2019 image of a black hole, the first one ever produced. Now, the team has conducted new observations of the supermassive black hole at the center of galaxy M87, revealing magnetic field lines around the void.
The Event Horizon Telescope is not a single instrument, but rather a network of radio telescopes spanning the globe. It includes famed facilities like the MIT Haystack Observatory, the Atacama Large Millimeter/submillimeter Array, and the Max Planck Institute for Radio Astronomy. By combining all these ultra-sensitive radio receivers, the EHT managed to image the supermassive black hole at the center of M87 in 2019. It was an amazing moment for science, as the image confirmed the previously only theoretical appearance of light swirling around the event horizon.
That wasn’t the end of the project, though. The team has continued to scan M87, which sits some 53 million light-years away, to gather more data. In the latest update, the EHT project has created a new version of the image that shows polarized light around the event horizon. These whirlpool-like lines describe the magnetic field surrounding the black hole, giving scientists another chance to test the latest hypotheses.
Most of the matter and energy spiraling around a black hole falls into the event horizon, never to be seen again. However, some of it gets flung outward. Some of that is the energy that makes up the famous EHT images. More dramatically, some of it forms a relativistic jet that extends thousands of light-years from the plane of the galaxy. Astronomers are still trying to work out how a black hole can create jets larger than the galaxy itself. Understanding how the magnetic field lines behave around the event horizon is an important piece of the puzzle, according to researchers.
With the new data, scientists are focusing on the role of ultra-hot magnetized gas. The polarized light indicates extremely strong magnetic fields around the event horizon help to push the gas away and keep it from falling into the event horizon. This is possible around a supermassive black hole like the one in M87 because the gravitational tidal forces are less intense than they would be around stellar-mass black holes. As physics tells us, gravity decreases with the square of the radius, so the spaghettification point is inside the event horizon of very large black holes. That’s just one of the many unintuitive things that make studying black holes so fascinating.