There were people sitting on chairs on a stage. They were all introduced, including Dr. Shep Doeleman, the Director of the Event Horizon Telescope (EHT) project. There was applause, and then there was silence as everyone in the room sat up to listen closely and to see the picture they all hoped to see. The presentation was succinct, but everyone whether in the room or watching remotely from their offices or homes was waiting for the anticipated announcement. These included scientists, post-docs, students, managers, politician, reporters, and other interested people watching and listening. These other interested people were called the “black-hole enthusiasts”. The work was described, including the development of a Very Long Baseline Interferometer the size of the earth with multiple sites at locations around the globe. Not all of the sites were able to view the target location at the same time, but this supported obtaining good data since as the world turned other sites/telescopes were able to view the target location in space. High levels of collaborative processes were required for the EHT team to be successful.
The target was in galaxy M87, also known as Virgo-Alpha. It is the largest galaxy in the Virgo cluster. At the heart of the galaxy is a super-massive black hole. The international team was seeking to “image”, to create a picture, of the event horizon of the black hole in M87.
The room was quiet. Dr. Doeleman turned toward the screen and pressed the button on his control. For a moment there was total silence followed by the soft clicks of cameras in the room. Then applause. It did not carry on for wave after wave, but it was solid and positive and excited. The applause stopped as everyone in the room leaned forward to see the image. Everyone quieted down as if there were a sound to be heard. Every ear strained; every eye refused to blink.
The image on the screen clearly showed the edge of the event horizon inside of which not even light can escape. Dr. Doeleman stressed that it was the work of numerous nations, their agencies, and their early-career and senior scientists that made possible the development of the pictures. The pictures were created from more than 5-petabytes of information. It was the hard work of all these people that enabled the image seen today to be extracted from the mass of data.
Enthusiasts at home leaned closer to their computer screen and rose on the edge of their chairs. The room was full of virtual attendees who wanted to be part of this announcement of what is truly scientific history.
The picture showed (“north” being up in the picture) a glowing mass of light, the swirl of particles around the heart of galaxy M87 before they cascade across the event horizon into the darkness. The colors in the maelstrom indicated the speed of photon emissions from the accretion flow toward the event horizon. There was a distinct rise in color as the relative speed of the light flowing towards the observing telescopes in 1-mm wavelength increased on the south edge of the ring. And there in the center, the darkness of no light escaping, the back hole. And between the two the crisp edge of the event horizon.
The first-of-its-kind image and the science and math behind it and the cooperation behind it all, leads us to a transformation of our understanding of black holes.
Congratulations to the entire team and all those who supported and continue to support them.
The image of the black hole is based on the image provided by the NSF-EHT. The map of Virgo is based on a map provided by IAU and Sky and Telescope.
The announcement and press briefing can be viewed at https://www.nsf.gov/news/special_reports/blackholes/ .