Scientists 'remaster' the first image ever captured of the black hole M87*
It's already been more than three years since humanity saw the first-ever image of a black hole in April 2019.
Since then, scientists from the Event Horizon Telescope (EHT) team also unveiled the first image of Sagittarius A*, the black hole at the heart of our galaxy.
Now, a team of researchers has "remastered" the image of M87*, the first ever black hole to be captured in an observation. A Harvard University press statement explains that they used theoretical predictions and state-of-the-art imaging algorithms to highlight a thin, bright ring of light created by photons flung to the rear of the black hole by intense gravity.
Remastering the image of M87*
This thin halo-like ring is obscured by the bright orange glow of the original image, but it was predicted by advanced simulations. The team's findings, published yesterday, August 16, in The Astrophysical Journal, are consistent with the theoretical predictions, and they provide a new perspective on the cosmic giants at the center of most galaxies.
"The approach we took involved leveraging our theoretical understanding of how these black holes look to build a customized model for the EHT data," Dominic Pesce, the study co-author, explained in Harvard's press statement. "Our model decomposes the reconstructed image into the two pieces that we care most about so that we can study both pieces individually rather than blended together."
Avery Broderick, who led the study, said the new "remaster" was possible because the EHT is a "computational instrument at its heart. It is as dependent on algorithms as it is upon steel. Cutting-edge algorithmic developments have allowed us to probe key features of the image while rendering the remainder in the EHT's native resolution."
The team behind the new development used new imaging software called THEMIS. This allowed them to isolate the thin ring from the original observations of the M87* black hole and also reveal the footprint of a powerful jet shooting out of the black hole. Essentially, the scientists removed elements from the black hole image to reveal what was behind it.
Imaging black holes
The EHT is a global network of telescopes that utilizes eight different observatories on four different continents. All of these are pointed at the same spot in the sky so that their data can be combined to form incredibly detailed observations.
"As we continue to add more telescopes and build out the next-generation EHT, the increased quality and quantity of data will allow us to place more definitive constraints on these signatures that we’re only now getting our first glimpses of," said co-author Paul Tiede, a CfA astrophysicist and EHT fellow at Harvard University's Black Hole Initiative.
Humans have now seen two black holes with their own eyes, and we're only at the beginning of the EHT's scientific journey. More than 300 international scientists worked together to bring us the image of our galaxy's black hole, and they will continue to work hard to uncover the mysteries of these cosmic beasts, which until recently only existed in theory.