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First photograph of a black hole in the history of Mankind

publicado a la‎(s)‎ 10 abr. 2019 10:05 por Plataforma Sites Dgac   [ actualizado el 21 ago. 2020 9:23 ]
The telescopes ALMA and APEX, located in Chile, contributed to achieve a fantastic photograph of a black hole in the giant and elliptical galaxy of Messier 87, 53.49 millions light-years from the Earth. The scientific work was announced on April 10, 2019.
Representation of a supermassive black hole that spins very fast and is surrounded by an accretion disk. This thin disk made up from rotating material is composed by the remains of a star similar to our Sun that was shredded by the black hole's tidal forces.
“We have 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 accomplished by a team of more than 200 researchers,” he added.

Black holes are extraordinary cosmic objects with enormous masses but extremely compact sizes. The presence of these objects affects their environment in extreme ways, warping spacetime and superheating any surrounding material.

“If immersed in a bright region, like a disc of glowing gas, we expect a black hole to create a dark region similar to a shadow — something predicted by Einstein’s general relativity that we’ve never seen before,” explained chair of the EHT Science Council Heino Falcke of Radboud University, the Netherlands. “This shadow, caused by the gravitational bending and 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 mass of M87’s black hole,” he explained.

Multiple calibration and imaging methods have revealed a ring-like structure with a dark central region — the black hole’s shadow — that persisted over multiple independent EHT observations.

“Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well,” remarks Paul T.P. Ho, EHT Board member and Director of the East Asian Observatory [5]. “This makes us confident about the interpretation of our observations, including our estimation of the black hole’s mass.”

“The confrontation of theory with observations is always a dramatic moment for a theorist. It was a relief and a source of pride to realise that the observations matched our predictions so well,” elaborated EHT Board member Luciano Rezzolla of Goethe Universität, Germany.

Creating the EHT was a formidable challenge which required upgrading and connecting a worldwide network of eight pre-existing telescopes deployed at a variety of challenging high-altitude sites. These locations included volcanoes in Hawaii and Mexico, mountains in Arizona and the Spanish Sierra Nevada, the Chilean Atacama Desert, and Antarctica.

Telescopes in Chile

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 [7]. 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.

European facilities and funding played a crucial role in this worldwide effort, with the participation of advanced European telescopes and the support from the European Research Council — particularly a €14 million grant for the BlackHoleCam project. Support from ESO, IRAM and the Max Planck Society was also key. “This result builds on decades of European expertise in millimetre astronomy”, commented Karl Schuster, Director of IRAM and member of the EHT Board.

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 close collaboration by 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. Key funding was provided by the US National Science Foundation (NSF), the EU's European Research Council (ERC), and funding agencies in East Asia.

“ESO is delighted to have significantly contributed to this result through its European leadership and pivotal role in two of the EHT’s component telescopes, located in Chile — ALMA and APEX,” commented ESO Director General Xavier Barcons. “ALMA is the most sensitive facility in the EHT, and its 66 high-precision antennas were critical in making the EHT a success.”

“We have achieved something presumed to be impossible just a generation ago,” concluded Doeleman. “Breakthroughs in technology, connections between the world's best radio observatories, and innovative algorithms all came together to open an entirely new window on black holes and the event horizon”, he added.

Source: Southern European Observatory
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