THE astronomers who gave the world its first true glimpse of a black hole have produced another landmark image, this time capturing the polarized light swirling around the same star-eating monster’s magnetic fields. But it is more than just a pretty picture. Never before has it been possible to measure polarization, which causes light waves to vibrate in a single plane, so close to the edge of a black hole. The new observations, based on data collected by the Event Horizon Telescope in 2017, are key to understanding how a galaxy can project streams of energy thousands of light-years outward from its core. More than 300 scientists, including eight researchers from the Shanghai Astronomical Observatory, Chinese Academy of Sciences, reported in a pair of studies on Wednesday. “From the new image, we can see a swirling polarization structure around, which tells us what the magnetic field looks like,” said Lu Rusen, a researcher at the Shanghai Astronomical Observatory. “The magnetic field information is hidden in the polarization amplitude and direction. It allows us to study the structure and the intensity of the magnetic field around the black hole,” he added. After releasing the historic image of the supermassive black hole at the heart of galaxy M87, more than 55 million light-years from Earth, the researchers discovered that a significant fraction of its surrounding light was polarized. Light can be polarized when it goes through certain filters, such as polarized sunglasses, or when it’s emitted in hot regions of space near magnetic fields. Just like polarized sunglasses reduce glare and help us see better, polarization allows astronomers to have a sharper view of the black hole and map magnetic field lines near its inner edge. The groundbreaking image of M87’s black hole and its shadow in polarized light allows astronomers to see for the first time this interplay between matter flowing in and being ejected. (SD-Agencies) |