The Event Horizon Telescope (EHT) — a planet-scale array of eight ground-based radio telescopes forged through international collaboration — was designed to capture images of a black hole. In coordinated press conferences across the globe, EHT researchers revealed that they succeeded, unveiling the first direct visual evidence of the supermassive black hole in the centre of Messier 87 and its shadow. The shadow of a black hole seen here is the closest we can come to an image of the black hole itself, a completely dark object from which light cannot escape. The black hole’s boundary — the event horizon from which the EHT takes its name — is around 2.5 times smaller than the shadow it casts and measures just under 40 billion km across. While this may sound large, this ring is only about 40 microarcseconds across — equivalent to measuring the length of a credit card on the surface of the Moon. Although the telescopes making up the EHT are not physically connected, they are able to synchronize their recorded data with atomic clocks — hydrogen masers — which precisely time their observations. These observations were collected at a wavelength of 1.3 mm during a 2017 global campaign. Each telescope of the EHT produced enormous amounts of data – roughly 350 terabytes per day – which was stored on high-performance helium-filled hard drives. These data were flown to highly specialised supercomputers — known as correlators — at the Max Planck Institute for Radio Astronomy and MIT Haystack Observatory to be combined. They were then painstakingly converted into an image using novel computational tools developed by the collaboration.
“I am also a part of the data processing and imaging teams, so was heavily involved in processing/ validating/checking the data and turning them into the images,” he told The Star in an email interview.
He said the team involved 200 international members, adding that he was among the first group of 20 people to see the black hole images.
Koay is still a fellow at ASIAA and at present, is actively involved in the observation at a newly constructed Greenland telescope in theArctic, which is part of the EHT assembly of land telescopes spread across the world and synchronised with atomic clocks.
“I was invited to join the Greenland telescope and EHT group because of my background and previous experience in radio astronomy. Of course, this project was too exciting for me to turn down!” he was quoted saying in the interview.
The Malaysian scientist who was a postdoctoral researcher at the Dark Cosmology Centre of the Niels Bohr Institute in the University of Copenhagen between 2013 and 2016 believes capturing the black hole image has opened up a new door in astrophysics.
“There’s much more to learn and much to improve, like the inclusion of new telescopes such as the Greenland telescope to achieve better image quality,” he told The Star.
Koay holds a doctorate from the International Centre for Radio Astronomy Research at Curtin University.
He returned to his hometown to give a lecture on the EHT project in Universiti Sains Malaysia (USM) on January 29.
His lecture on the project is still available for viewing on the Physics Coffee Talk, a Facebook page set up by a group of USM students to discuss physics.
MALAY MAIL
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