The team behind the first ever image of a black hole can now observe the same celestial gargantuan with greater definition than ever before.
On Tuesday, the Event Horizon Telescope (EHT) team announced that their global network of radio telescopes, which turns Earth into one giant virtual telescope, can observe at a new radio frequency. This means a few things. First, the team can get crisper imagery of the supermassive black hole at the center of galaxy M87, which starred in the first ever image of a black hole, taken in 2017 and published in 2019. Second, having an additional frequency means the team can play with color.
“This new ‘color vision’ allows us to tease apart the effects of Einstein’s gravity from the hot gas and magnetic fields that feed the black holes and launch powerful jets that stream over galactic distances,” Sheperd “Shep” Doeleman, astrophysicist and Founding Director of the EHT, said in an announcement published Tuesday.
Two is better than one
Doeleman tells Inverse that supermassive black holes are busy places. Seeing two frequencies would reveal more of its organized chaos. The team has published simulation images to depict how the new frequency changes the view.
“When you have two separate frequencies, you’re able to tease apart different effects around the black hole,” Doeleman says.
Albert Einstein predicted that gravity bends all light, across all wavelengths, in the same way. Right around the black hole’s shadow, where gravity is so strong that not even light can reflect back out, data across both frequencies may look the same.
But farther away from the event horizon, other phenomena like the black hole’s jets of superheated plasma will look differently from one frequency to the next.
Seeing in color
Having two sets of information allows for color. The data from the telescopes is radio, a wavelength of light invisible to human eyes. The single color of existing EHT images are packed with information at 230 GHz. But now that EHT can take observations at 345 GHz, imagery specialists can add a new color to the golden ring. This will be exciting to view not only as a still image, but eventually, as a motion picture.
Doeleman and other researchers hope the telescopes in the EHT network will be able to take not just two radio wavelengths at the same time, but eventually three.
“The EHT's successful observation at 345 GHz is a major scientific milestone,” Lisa Kewley, Director of the Center for Astrophysics | Harvard & Smithsonian, said in the announcement. “By pushing the limits of resolution, we’re achieving the unprecedented clarity in the imaging of black holes we promised early on, and setting new and higher standards for the capability of ground-based astrophysical research.”
