First M87 Event Horizon Telescope Results. II. Array and Instrumentation

Kazunori Akiyama , Antxon Alberdi , Walter Alef , Keiichi Asada , Rebecca Azulay , Anne-Kathrin Baczko , David Ball , Mislav Baloković , John Barrett , Dan Bintley , Lindy Blackburn , Wilfred Boland , Katherine L. Bouman , Geoffrey C. Bower , Michael Bremer (1) , Christiaan D. Brinkerink , Roger Brissenden , Silke Britzen , Avery E. Broderick , Dominique Broguiere (1) , Thomas Bronzwaer , Do-Young Byun , John E. Carlstrom , Andrew Chael , Chi-Kwan Chan , Shami Chatterjee , Koushik Chatterjee , Ming-Tang Chen , Yongjun Chen , Ilje Cho , Pierre Christian , John E. Conway , James M. Cordes , Geoffrey B. Crew , Yuzhu Cui , Jordy Davelaar , Mariafelicia de Laurentis , Roger Deane , Jessica Dempsey , Gregory Desvignes , Jason Dexter , Sheperd S. Doeleman , Ralph P. Eatough , Heino Falcke , Vincent L. Fish , E. Fomalont , Raquel Fraga-Encinas , Per Friberg , Christian M. Fromm , José L. Gómez , Peter Galison , Charles F. Gammie , Roberto García (1) , Olivier Gentaz (1) , Boris Georgiev , Ciriaco Goddi , Roman Gold , Minfeng Gu , Mark Gurwell , Kazuhiro Hada , Michael H. Hecht , Ronald Hesper , Luis C. Ho , Paul Ho , Mareki Honma , Chih-Wei L. Huang , Lei Huang , David H. Hughes , Shiro Ikeda , Makoto Inoue , Sara Issaoun , David J. James , Buell T. Jannuzi , Michael Janssen , Britton Jeter , Wu Jiang , Michael D. Johnson , Svetlana Jorstad , Taehyun Jung , Mansour Karami , Ramesh Karuppusamy , Tomohisa Kawashima , Garrett K. Keating , Mark Kettenis , Jae-Young Kim , Junhan Kim , Jongsoo Kim , Motoki Kino , Jun Yi Koay , Patrick M. Koch , Shoko Koyama , Michael Kramer , Carsten Kramer (1) , Thomas P. Krichbaum , Cheng-Yu Kuo , Tod R. Lauer , Sang-Sung Lee , Yan-Rong Li , Zhiyuan Li , Michael Lindqvist , Kuo Liu , Elisabetta Liuzzo , Wen-Ping Lo , Andrei P. Lobanov , Laurent Loinard , Colin Lonsdale , Ru-Sen Lu , Nicholas R. Macdonald , Jirong Mao , Sera Markoff , Daniel P. Marrone , Alan P. Marscher , Iván Martí-Vidal , Satoki Matsushita , Lynn D. Matthews , Lia Medeiros , Karl M. Menten , Yosuke Mizuno , Izumi Mizuno , James M. Moran , Kotaro Moriyama , Monika Moscibrodzka , Cornelia Müller , Hiroshi Nagai , Neil M. Nagar , Masanori Nakamura , Ramesh Narayan , Gopal Narayanan , Iniyan Natarajan , Roberto Neri (1) , Chunchong Ni , Aristeidis Noutsos , Hiroki Okino , Héctor Olivares , Gisela N. Ortiz-León , Feryal Özel , Daniel C.M. Palumbo , Nimesh Patel , Ue-Li Pen , Dominic W. Pesce , Vincent Piétu (1) , Richard Plambeck , Aleksandar Popstefanija , Oliver Porth , Ben Prather , Jorge A. Preciado-López , Dimitrios Psaltis , Hung-Yi Pu , Venkatessh Ramakrishnan , Ramprasad Rao , Mark G. Rawlings , Alexander W. Raymond , Luciano Rezzolla , Bart Ripperda , Freek Roelofs , Alan Rogers , Eduardo Ros , Mel Rose , Arash Roshanineshat , Helge Rottmann , Alan L. Roy , Chet Ruszczyk , Benjamin R. Ryan , Kazi L.J. Rygl , Salvador Sánchez (2) , David Sánchez-Arguelles , Mahito Sasada , Tuomas Savolainen , F. Peter Schloerb , Karl-Friedrich Schuster (1) , Lijing Shao , Zhiqiang Shen , Des Small , Bong Won Sohn , Jason Soohoo , Fumie Tazaki , Paul Tiede , Remo P.J. Tilanus , Michael Titus , Kenji Toma , Pablo Torne (2) , Tyler Trent , Sascha Trippe , Shuichiro Tsuda , Ilse van Bemmel , Huib Jan van Langevelde , Daniel R. van Rossum , Jan Wagner , John Wardle , Jonathan Weintroub , Norbert Wex , Robert Wharton , Maciek Wielgus , George N. Wong , Qingwen Wu , André Young , Ken Young , Ziri Younsi , Feng Yuan , Ye-Fei Yuan , J. Anton Zensus , Guangyao Zhao , Shan-Shan Zhao , Ziyan Zhu , Juan-Carlos Algaba , Alexander Allardi , Rodrigo Amestica , Uwe Bach , Christopher Beaudoin , Bradford A. Benson , Ryan Berthold , Jay M. Blanchard , Ray Blundell , Sandra Bustamente , Roger Cappallo , Edgar Castillo-Domínguez , Chih-Cheng Chang , Shu-Hao Chang , Song-Chu Chang , Chung-Chen Chen , Ryan Chilson , Tim C. Chuter , Rodrigo Córdova Rosado , Iain M. Coulson , Thomas M. Crawford , Joseph Crowley , John David (2) , Mark Derome , Matthew Dexter , Sven Dornbusch , Kevin A. Dudevoir , Sergio A. Dzib , Chris Eckert , Neal R. Erickson , Wendeline B. Everett , Aaron Faber , Joseph R. Farah , Vernon Fath , Thomas W. Folkers , David C. Forbes , Robert Freund , Arturo I. Gómez-Ruiz , David M. Gale , Feng Gao , Gertie Geertsema , David A. Graham , Christopher H. Greer , Ronald Grosslein , Frédéric Gueth (1) , Nils W. Halverson , Chih-Chiang Han , Kuo-Chang Han , Jinchi Hao , Yutaka Hasegawa , Jason W. Henning , Antonio Hernández-Gómez (3) , Rubén Herrero-Illana , Stefan Heyminck , Akihiko Hirota , James Hoge , Yau-De Huang , C.M. Violette Impellizzeri , Homin Jiang , Atish Kamble , Ryan Keisler , Kimihiro Kimura , Yusuke Kono , Derek Kubo , John Kuroda , Richard Lacasse , Robert A. Laing , Erik M. Leitch , Chao-Te Li , Lupin C.-C. Lin , Ching-Tang Liu , Kuan-Yu Liu , Li-Ming Lu , Ralph G. Marson , Pierre L. Martin-Cocher , Kyle D. Massingill , Callie Matulonis , Martin P. Mccoll , Stephen R. Mcwhirter , Hugo Messias , Zheng Meyer-Zhao , Daniel Michalik , Alfredo Montaña , William Montgomerie , Matias Mora-Klein , Dirk Muders , Andrew Nadolski , Santiago Navarro (2) , Chi H. Nguyen , Hiroaki Nishioka , Timothy Norton , George Nystrom , Hideo Ogawa , Peter Oshiro , Tomoaki Oyama , Stephen Padin , Harriet Parsons , Scott N. Paine , Juan Peñalver (2) , Neil M. Phillips , Michael Poirier , Nicolas Pradel , Rurik A. Primiani , Philippe A. Raffin , Alexandra S. Rahlin , George Reiland , Christopher Risacher (1) , Ignacio Ruiz (2) , Alejandro F. Sáez-Madaín , Remi Sassella (1) , Pim Schellart , Paul Shaw , Kevin M. Silva , Hotaka Shiokawa , David R. Smith , William Snow , Kamal Souccar , Don Sousa , T.K. Sridharan , Ranjani Srinivasan , William Stahm , Antony A. Stark , Kyle Story , Sjoerd T. Timmer , Laura Vertatschitsch , Craig Walther , Ta-Shun Wei , Nathan Whitehorn , Alan R. Whitney , David P. Woody , Jan G.A. Wouterloot , Melvin Wright , Paul Yamaguchi , Chen-Yu Yu , Milagros Zeballos , Lucy Ziurys

1 IRAM - Institut de RadioAstronomie Millimétrique
2 IRAM - Instituto de RadioAstronomía Milimétrica
3 IRAP - Institut de recherche en astrophysique et planétologie

The Event Horizon Telescope(EHT)is a very long baseline interferometry (VLBI) array that comprises millimeter- and submillimeter-wavelength telescopes separated by distances comparable to the diameter of the Earth. At a nominal operating wavelength of∼1.3 mm, EHT angular resolution(λ/D)is∼25μas, which is sufficient to resolve nearby supermassive black hole candidates on spatial and temporal scales that correspond to their event horizons. With this capability, the EHT scientific goals are to probe general relativistic effects in the strong-field regime and to study accretion and relativistic jet formation near the black hole boundary. In this Letterwe describe the system design of the EHT, detail the technology and instrumentation that enable observations, and provide measures of its performance. Meeting the EHT science objectives has required several key developments that have facilitated the robust extension of the VLBI technique to EHT observing wavelengths and the production of instrumentation that can be deployed on a heterogeneous array of existing telescopes and facilities. To meet sensitivity requirements, high-bandwidth digital systems were developed that process data at rates of 64 gigabit s−1, exceeding those of currently operating cm-wavelength VLBI arrays by more than an order of magnitude. Associated improvements include the development of phasing systems at array facilities, new receiver installation at several sites, and the deployment of hydrogen maser frequency standards to ensure coherent data capture across the array. These efforts led to the coordination and execution of the first Global EHT observations in2017 April, and to event-horizon-scale imaging of the supermassive black hole candidate in M87.

Mots clés: black hole physics; galaxies: individual; Galaxy: center; gravitational lensing: strong; instrumentation: interferometers; techniques: high angular resolution

Domaines: Astrophysique [astro-ph]

Kazunori Akiyama, Antxon Alberdi, Walter Alef, Keiichi Asada, Rebecca Azulay, et al.. First M87 Event Horizon Telescope Results. II. Array and Instrumentation. Astrophys.J.Lett., 2019, 875 (1), pp.L2. ⟨10.3847/2041-8213/ab0c96⟩. ⟨hal-02404866⟩