The Horizon Event Telescope (EHT), a set of eight ground-based and planetary radio telescopes forged as part of an international collaboration, was designed to capture the images of a black hole. Today, at coordinated press conferences around the world, EHT researchers revealed that they had succeeded, unveiling the first direct visual evidence of a supermassive black hole and its shadow.
This breakthrough was announced today in a series of six articles published in a special issue of The Astrophysical Journal Letters. The image reveals the black hole in the center of Messier 87, a massive galaxy located in the group of nearby Virgo galaxies. This black hole is located 55 million light-years from Earth and has a mass 6.5 billion times greater than that of the Sun.
EHT connects telescopes around the world to form an unprecedented virtual telescope the size of the Earth. The EHT offers scientists a new way to study the most extreme objects in the Universe predicted by Einstein's General Relativity during the centennial year of the historical experiment that first confirmed the theory.
"We took the first picture of a black hole," said Sheperd S. Doeleman, director of the EHT project of the Center for Astrophysics | Harvard and Smithsonian. "It is an extraordinary scientific feat accomplished by a team of more than 200 researchers."
Black holes are extraordinary cosmic objects with huge masses but extremely compact dimensions. The presence of these objects affects their environment in an extreme way, distorting the space-time and overheating the surrounding materials.
"If they're immersed in an illuminated area, like a sparkling gas disk, we expect a black hole to create a dark, shadow-like region – that's the general relativity of". Einstein had predicted, which we had never seen before, "explained the chairman of the EHT Scientific Council Heino Falcke of Radboud University, the Netherlands. "This shadow, caused by gravitational bending and the capture of light by the horizon of events, says a lot about the nature of these fascinating objects and allowed us to measure the enormous mass of the black hole of M87. "
Several calibration and imaging methods revealed a ring structure with a dark central region – the shadow of the black hole – that persisted in several independent EHT observations.
"Once we were sure we had imagined the shadow, we could compare our observations to many computer models including the physics of distorted space, superheated matter, and strong magnetic fields. Many of the features of the observed image fit surprisingly well with our theoretical understanding, "notes Paul TP Ho, ISE Board member and Director of the Observatory of the I & # 39; 39 East Asia. "This makes us confident about the interpretation of our observations, including our estimate of the mass of the black hole."
"The confrontation of theory with observations is always a dramatic moment for a theorist. It was a relief and a source of pride to find that the observations corresponded so well to our forecasts, "explained Luciano Rezzolla, member of the board of directors of the ESS, of the Goethe Universität, in Germany.
The creation of the ISE was a daunting challenge that required upgrading and connecting a global network of eight pre-existing telescopes deployed on various challenging high-altitude sites. These sites included volcanoes in Hawaii and Mexico, mountains in Arizona and the Spanish Sierra Nevada, the Atacama Desert in Chile and Antarctica.
EHT observations use a technique called Very Long Baseline Interferometry (VLBI) that synchronizes telescope installations around the world and exploits the rotation of our planet to form a huge Earth-size telescope, observing at a length of 30 feet. 1.3 mm wave. VLBI allows the EHT to reach an angular resolution of 20 micro-arcseconds, enough to read a newspaper in New York at a Paris café.
The telescopes that contributed to this result were ALMA, APEX, the 30 meter IRAM telescope, the James Clerk Maxwell telescope, the large Alfonso Serrano millimeter telescope, the submillimeter array, the submillimeter telescope and the South Pole. Petabytes of raw data from the telescopes were combined by highly specialized supercomputers hosted by the Max Planck Institute for Radioastronomy and MIT Haystack observatory.
European facilities and funding played a crucial role in this global effort, with the participation of advanced European telescopes and the support of the European Research Council, including a € 14 million grant for the BlackHoleCam project. Support from ESO, IRAM and Max Planck was also essential. "This result builds on decades of European expertise in millimetric astronomy," commented Karl Schuster, director of IRAM and a member of the EHT board of directors.
The Horizon Event Telescope (EHT) – a set of eight ground-based and planetary radio telescopes forged as part of an international collaboration – was designed to capture images of a black hole. At coordinated press conferences worldwide, ISE researchers revealed that they had succeeded, unveiling the first direct visual evidence of a supermassive black hole and its shadow. This 17-minute film explores the efforts that led to this historical picture, from Einstein's and Schwarzschild's science to the struggles and successes of the EHT collaboration. Credit: ESO
The construction of EIS and the observations announced today represent the culmination of decades of observational, technical and theoretical work. This example of global team work required close collaboration from researchers around the world. Thirteen partner institutions collaborated to create the ISE, using both pre-existing infrastructure and support from various organizations. Key funding has been provided by the US National Science Foundation (NSF), the European Research Council (ERC) and funding agencies in East Asia.
The Horizon Event Telescope (EHT) – a set of eight ground-based and planetary radio telescopes forged as part of an international collaboration – was designed to capture images of a black hole. At coordinated press conferences worldwide, ISE researchers revealed that they had succeeded, unveiling the first direct visual evidence of a supermassive black hole and its shadow.
"ESO is pleased to have made a significant contribution to this achievement through its European leadership and pivotal role in two of ESH's component telescopes located in Chile – ALMA and APEX," said the Director General. ESO, Xavier Barcons. "ALMA is the most sensitive installation of the EHT, and its 66 high-precision antennas have been essential to the success of the EHT."
In anticipation of the first image of a black hole, Jordy Davelaar and his colleagues built a virtual reality simulation of one of these fascinating astrophysical objects. Their simulation shows a black hole surrounded by luminous matter. This material disappears into the black hole in the manner of a vortex, and the extreme conditions cause it to become a glowing plasma. The emitted light is then deflected and deformed by the powerful gravity of the black hole.
"We did something that was presumed impossible just a generation ago," Doeleman concluded. "Technological breakthroughs, connections between the world's best radio observatories and innovative algorithms have all come together to open a new window on black holes and the horizon of events."
The impression of this artist represents the black hole in the heart of the huge elliptical galaxy M87. This black hole was chosen as an observation object by the Event Horizon telescope to change the paradigm. The overheated material surrounding the black hole is shown.
The impression of this artist represents the black hole in the heart of the huge elliptical galaxy M87. This black hole was chosen as an observation object by the Event Horizon telescope to change the paradigm. The overheated material surrounding the black hole is presented, as well as the relativistic jet launched by the black hole of M87.