Zooming in on the black hole and jet of Messier 87. Credit: ESO/L. Calçada, Digitized Sky Survey 2, ESA/Hubble, RadioAstron, De Gasperin et al., Kim et al., R. Lu and E. Ros (GMVA), S. Dagnello (NRAO/AUI/NSF).
Astronomers today unveiled new images of the black hole at the center of galaxy M87, showing both a lighter version of the black hole’s glowing ring and its powerful jet together in the same image for the first time. The Event Horizon Telescope (EHT) first imaged the black hole in 2017; this new image is based on data collected by the Global Millimeter VLBI Array (GMVA), which captured radio emissions at a slightly different but scientifically significant wavelength. The details of the new observational data, image processing methods and associated computer simulations are described in a new paper published in the journal Nature.
“This is the first image where we can pinpoint where the ring is relative to the powerful jet escaping from the central black hole,” said study co-author Kazunori Akiyama of MIT’s Haystack Observatory, who developed the imaging software used to visualize the black hole. “Now we can delve deeper into questions such as how particles are accelerated and heated and many other mysteries surrounding the black hole.”
As we previously reported, the EHT is actually a collection of telescopes scattered around the world, including hardware from Hawaii to Europe and from the South Pole to Greenland. The “telescope” is created through a process called interferometry, in which light collected at various locations is used to build an image with a resolution equivalent to a giant telescope (one that is as big as is that it appears to be as large as the distance between the most distant locations of the individual telescopes).
Scientists working on the EHT made headlines worldwide in 2019 when they revealed the first direct image of the aft hole in the center of the M87 galaxy. Two years later, EHT researchers released another image of the same black hole, this time showing what it looked like in polarized light. The ability to measure that polarization for the first time — a signature of magnetic fields at the black hole’s edge — provided new insight into how black holes gobble up matter and emit powerful jets from their cores. Astronomers were also able to map the magnetic field lines at the inner rim and study the interaction between matter flowing in and being blown out.
And earlier this month, four members of the EHT collaboration applied a new machine learning technique called PRIMO (principal-component interferometric modeling) to the original 2017 data, giving that famous image its first makeover. PRIMO analyzed more than 30,000 simulated images of black holes accreting gas, taking into account many different models for how this accretion of matter occurs. Structural patterns were sorted by how often they showed up in the simulations, and PRIMO then mixed them to produce a new, true-to-life image of the black hole.
