ASTRON congratulates partner institute JIVE (The Joint Institute for VLBI ERIC) with their contribution to the observations of the gargantuan black hole at the heart of distant galaxy Messier 87.
Published by the editorial team, 11 April 2019
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. Yesterday, in coordinated press conferences across the globe, EHT researchers revealed that they have succeeded, unveiling the first direct visual evidence of a supermassive black hole and its shadow.
This breakthrough was announced yesterday in a series of six papers published in a special issue of The Astrophysical Journal Letters. The image reveals the black hole at the centre of Messier 87, a massive galaxy in the nearby Virgo galaxy cluster. This black hole resides 55 million light-years from Earth and has a mass 6.5-billion times that of the Sun.
The telescopes contributing to this result were ALMA, APEX, the IRAM 30-meter telescope, the James Clerk Maxwell Telescope, the Large Millimeter Telescope Alfonso Serrano, the Submillimeter Array, the Submillimeter Telescope, and the South Pole Telescope. Petabytes of raw data from the telescopes were combined by highly specialised supercomputers hosted by the Max Planck Institute for Radio Astronomy and MIT Haystack Observatory.
As part of the EHT project, JIVE developed software to calibrate data from the observations. "The calibration is especially challenging at these short wavelengths. To obtain a signal, the data from different telescopes have to be combined with extremely high precision," explains Ilse van Bemmel from JIVE. "The software tools are now publicly available, enabling everyone to verify the EHT results, as well as ensuring future VLBI observations at all wavelengths are easier and more accessible."
"It is truly amazing that we have seen this shadow for the first time," says Huib van Langevelde. "The black hole in M87 required all millimeter telescopes in the world, including ALMA, to work in perfect synchronicity. The subsequent data calibration, imaging, analysis and theoretical models posed a major challenge for our international collaboration."
ASTRON researcher Zheng Meyer is one of the 200 scientists involved; she worked at the ALMA Phase-up project (APP) from 2013 until October 2015. The APP project was crucial for the EHT observations, in order to deliver a very high resolution. ASTRON is a partner in the JIV-ERIC and hosts the institute. However, ASTRON telescopes did not contribute to the EHT observations, as they are specialised for different wavelengths than the telescopes used by the EHT team. ASTRON looks forward to future developments in VLBI with projects such as the Square Kilometre Array, which will further increase our understanding of our galaxy.
Here you can read the complete press release on the website of JIVE.