The Event Horizon Telescope (EHT), a planetary-scale badembly of eight terrestrial radio telescopes forged through international collaboration, was designed to capture images of a dungeon. Today, at coordinated press conferences around the world, EHT researchers reveal that they have succeeded, revealing the first direct visual evidence of a supermbadive 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 mbadive galaxy in the nearby cluster of Virgo galaxies. This black hole resides 55 million light years from Earth and has a mbad of 6.5 billion times that of the Sun.
The EHT connects telescopes around the world to form a virtual telescope the size of the Earth unprecedented. The EHT offers scientists a new way of studying the most extreme objects in the Universe predicted by Einstein's general relativity during the centennial year of the historical experiment that confirmed the theory for the first time.
"We've taken the first picture of a black hole," said EHT project director Sheperd S. Doeleman of the Center for Astrophysics | Harvard & Smithsonian. "This is an extraordinary scientific feat done by a team of more than 200 researchers."
Black holes are extraordinary cosmic objects with huge mbades but extremely compact sizes. The presence of these objects affects their surroundings in an extreme way, deforming the space-time and overheating any surrounding material.
"If we are immersed in a bright region, like a disk of incandescent gas, we hope that a black hole creates a dark region similar to a shadow, something predicted by the general relativity of Einstein that we have never seen before," explained the president of EHT. . Heino Falcke Scientific Council of the Radboud University, The Netherlands. "This shadow, caused by the gravitational curvature and the capture of light by the event horizon, reveals a lot about the nature of these fascinating objects and has allowed us to measure the enormous mbad of the black hole of M87".
Multiple methods of calibration and imaging have revealed a ring-shaped structure with a dark central region, the shadow of the black hole, that persisted during multiple independent observations of EHT.
"Once we were sure that we had photographed the shadow, we could compare our observations with extensive computer models that include the physics of warped space, superheated matter and strong magnetic fields. Many of the characteristics of the observed image coincide surprisingly well with our theoretical understanding, "says Paul TP Ho, member of the EHT Board and Director of the East Asia Observatory." This makes us confident in the interpretation of our observations, including our black hole mbad estimate ".
"The confrontation of theory with observations is always a dramatic moment for a theorist. It was a relief and a source of pride to realize that the observations coincided with our predictions, "explained Luciano Rezzolla, member of the EHT Board of Goethe Universität, Germany.
Creating the EHT was a formidable challenge that required updating and connecting a worldwide network of eight pre-existing telescopes deployed in a variety of challenging high-altitude sites. These locations included volcanoes in Hawaii and Mexico, mountains in Arizona and the Spanish Sierra Nevada, the Atacama Desert of Chile and Antarctica.
The EHT observations use a technique called very long baseline interferometry (VLBI) that synchronizes the installations of telescopes around the world and exploits the rotation of our planet to form a huge telescope the size of the Earth by observing a wavelength of 1.3 mm. VLBI allows the EHT to achieve an angular resolution of 20 microarcseconds, enough to read a newspaper in New York from a café in Paris.
The telescopes that contributed to this result were: SOUL, APEX, the 30 meter IRAM telescope, the James Clerk Maxwell Telescope, the Alfonso Serrano Large Millimeter Telescope, the Submillimeter Matrix, the Submillimeter Telescope and the South Pole Telescope. Petabytes of unprocessed data from the telescopes were combined by highly specialized supercomputers organized by the Max Planck Institute for Radio Astronomy and MIT Observatory of Pajares.
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, in particular a subsidy of 14 million euros for the BlackHoleCam project. The support of ESO, IRAM and the Max Planck Society was also key. "This result is based on decades of European experience in millimeter astronomy," said Karl Schuster, Director of IRAM and member of the Board of EHT.
The Event Horizon Telescope (EHT), a planetary-scale set of eight terrestrial radio telescopes forged through international collaboration, was designed to capture images of a black hole. At coordinated press conferences around the world, EHT researchers revealed that they were successful, revealing the first direct visual evidence of a supermbadive black hole and its shadow. This 17-minute film explores the efforts that led to this historical image, from the science of Einstein and Schwarzschild to the struggles and successes of the EHT collaboration. Credit: ESO
The construction of the EHT and the observations announced today represent the culmination of decades of observational, technical and theoretical work. This example of global teamwork required a close collaboration of researchers from around the world. Thirteen partner institutions worked together to create the EHT, using both pre-existing infrastructure and support from a variety of agencies. The National Science Foundation (NSF) of the US UU., The European Research Council of the EU (ERC) and funding agencies in East Asia provided key funds.
The Event Horizon Telescope (EHT), a planetary-scale set of eight terrestrial radio telescopes forged through international collaboration, was designed to capture images of a black hole. At coordinated press conferences around the world, EHT researchers revealed that they were successful, revealing the first direct visual evidence of a supermbadive black hole and its shadow.
"ESO is delighted to have contributed significantly to this result through its European leadership and its pivotal role in two of EHT's component telescopes located in Chile: ALMA and APEX," said ESO General Director Xavier Barcons. "ALMA is the most sensitive installation in the EHT, and its 66 high-precision antennas were critical for the EHT to be a success."
Anticipating the first image of a black hole, Jordy Davelaar and his colleagues built a virtual reality simulation of one of these fascinating astrophysical objects. His simulation shows a black hole surrounded by luminous matter. This matter disappears in the black hole similar to a vortex, and extreme conditions cause it to become a bright plasma. The emitted light is deflected and deformed by the powerful gravity of the black hole.
"We have achieved something that is presumed to be impossible only a generation ago," Doeleman concluded. "Advances in technology, connections between the best radio observatories in the world and innovative algorithms came together to open a completely new window on black holes and the event horizon."
The impression of this artist shows the black hole in the heart of the huge elliptical galaxy M87. This black hole was chosen as the object of paradigm shift observations by the Event Horizon Telescope. The superheated material that surrounds the black hole is displayed.
The impression of this artist shows the black hole in the heart of the huge elliptical galaxy M87. This black hole was chosen as the object of paradigm shift observations by the Event Horizon Telescope. It shows the superheated material that surrounds the black hole, just like the relativistic jet released by the black hole of M87.