Event Horizon Telescope

Event Horizon Telescope
Alternative namesEHT Edit this on Wikidata
Established2009; 15 years ago (2009)
Websiteeventhorizontelescope.org Edit this at Wikidata
Telescopes
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The Event Horizon Telescope (EHT) is a telescope array consisting of a global network of radio telescopes. The EHT project combines data from several very-long-baseline interferometry (VLBI) stations around Earth, which form a combined array with an angular resolution sufficient to observe objects the size of a supermassive black hole's event horizon. The project's observational targets include the two black holes with the largest angular diameter as observed from Earth: the black hole at the center of the supergiant elliptical galaxy Messier 87, and Sagittarius A*, at the center of the Milky Way.[1][2]

The Event Horizon Telescope project is an international collaboration that was launched in 2009[1] after a long period of theoretical and technical developments. On the theory side, work on the photon orbit[3] and first simulations of what a black hole would look like[4] progressed to predictions of VLBI imaging for the Galactic Center black hole, Sgr A*.[5][6] Technical advances in radio observing moved from the first detection of Sgr A*,[7] through VLBI at progressively shorter wavelengths, ultimately leading to detection of horizon scale structure in both Sgr A* and M87.[8][9] The collaboration now comprises over 300[10] members, and 60 institutions, working in over 20 countries and regions.[11]

The first image of a black hole, at the center of galaxy Messier 87, was published by the EHT Collaboration on April 10, 2019, in a series of six scientific publications.[12] The array made this observation at a wavelength of 1.3 mm and with a theoretical diffraction-limited resolution of 25 microarcseconds. In March 2021, the Collaboration presented, for the first time, a polarized-based image of the black hole which may help better reveal the forces giving rise to quasars.[13] Future plans involve improving the array's resolution by adding new telescopes and by taking shorter-wavelength observations.[2][14] On 12 May 2022, astronomers unveiled the first image of the supermassive black hole at the center of the Milky Way, Sagittarius A*.[15] Recently EHT Project has reported to have reached the resolution of 870 μm at 345 GHz, that is pair to 19 μas, the best angular resolution at astronomical facilities on Earth.[16]

  1. ^ a b Doeleman, Sheperd (June 21, 2009). "Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole". Astro2010: The Astronomy and Astrophysics Decadal Survey, Science White Papers. 2010: 68. arXiv:0906.3899. Bibcode:2009astro2010S..68D.
  2. ^ a b The Event Horizon Telescope Collaboration (April 10, 2019). "First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole". The Astrophysical Journal Letters. 875 (1): L1. arXiv:1906.11238. Bibcode:2019ApJ...875L...1E. doi:10.3847/2041-8213/ab0ec7. S2CID 145906806.
  3. ^ Bardeen, James (1973). "Black holes. Edited by C. DeWitt and B. S. DeWitt". Les Houches École d'Été de Physique Théorique. Bibcode:1973blho.conf.....D.
  4. ^ Luminet, Jean-Pierre (July 31, 1979). "Image of a spherical black hole with thin accretion disk". Astronomy and Astrophysics. 75: 228. Bibcode:1979A&A....75..228L.
  5. ^ Falcke, Heino; Melia, Fulvio; Agol, Eric (January 1, 2000). "Viewing the Shadow of the Black Hole at the Galactic Center". The Astrophysical Journal Letters. 528 (1): L13–L16. arXiv:astro-ph/9912263. Bibcode:2000ApJ...528L..13F. doi:10.1086/312423. PMID 10587484. S2CID 119433133.
  6. ^ Broderick, Avery; Loeb, Abraham (April 11, 2006). "Imaging optically-thin hotspots near the black hole horizon of Sgr A* at radio and near-infrared wavelengths". Monthly Notices of the Royal Astronomical Society. 367 (3): 905–916. arXiv:astro-ph/0509237. Bibcode:2006MNRAS.367..905B. doi:10.1111/j.1365-2966.2006.10152.x. S2CID 16881360.
  7. ^ Balick, Bruce; Brown, R.L. (December 1, 1974). "Intense sub-arcsecond structure in the galactic center". The Astrophysical Journal. 194 (1): 265–279. Bibcode:1974ApJ...194..265B. doi:10.1086/153242. S2CID 121802758.
  8. ^ Doeleman, Sheperd (September 4, 2008). "Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre". Nature. 455 (7209): 78–80. arXiv:0809.2442. Bibcode:2008Natur.455...78D. doi:10.1038/nature07245. PMID 18769434. S2CID 4424735.
  9. ^ Doeleman, Sheperd (October 19, 2012). "Jet-launching structure resolved near the supermassive black hole in M87". Science. 338 (6105): 355–358. arXiv:1210.6132. Bibcode:2012Sci...338..355D. doi:10.1126/science.1224768. PMID 23019611. S2CID 37585603.
  10. ^ "Winners Of The 2020 Breakthrough Prize In Life Sciences, Fundamental Physics And Mathematics Announced". Breakthrough Prize. Retrieved March 15, 2020.
  11. ^ "Event Horizon Telescope 2022". March 12, 2022.
  12. ^ Shep Doeleman, on behalf of the EHT Collaboration (April 2019). "Focus on the First Event Horizon Telescope Results". The Astrophysical Journal Letters. Retrieved April 10, 2019.
  13. ^ Overbye, Dennis (March 24, 2021). "The Most Intimate Portrait Yet of a Black Hole – Two years of analyzing the polarized light from a galaxy's giant black hole has given scientists a glimpse at how quasars might arise". The New York Times. Retrieved March 25, 2021.
  14. ^ Cite error: The named reference aasnova-20190410 was invoked but never defined (see the help page).
  15. ^ Overbye, Dennis (May 12, 2022). "Has the Milky Way's Black Hole Come to Light? – The Event Horizon Telescope reaches again for a glimpse of the 'unseeable'". The New York Times. Retrieved May 12, 2022.
  16. ^ Alexander W. Raymond et al 2024 AJ 168 130