First M87 Event Horizon Telescope Results. II. Array and Instrumentation
Journal article, 2019
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 ∼25 μas, 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 Letter we 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 in 2017 April, and to event-horizon-scale imaging of the supermassive black hole candidate in M87.
techniques: high angular resolution
instrumentation: interferometers
gravitational lensing: strong
galaxies: individual (M87)
Galaxy: center
black hole physics
Author
Kazunori Akiyama
Harvard University
National Radio Astronomy Observatory
National Astronomical Observatory of Japan
Massachusetts Institute of Technology (MIT)
Antxon Alberdi
Institute of Astrophysics of Andalusia (IAA)
Walter Alef
Max Planck Society
K. Asada
National Taiwan University
R. Azulay
Universitat de Valencia
Max Planck Society
A. K. Baczko
Max Planck Society
David Ball
University of Arizona
Mislav Baloković
Harvard University
Harvard-Smithsonian Center for Astrophysics
John Barrett
Massachusetts Institute of Technology (MIT)
Dan Bintley
East Asian Observatory
Lindy Blackburn
Harvard-Smithsonian Center for Astrophysics
Harvard University
W. Boland
Nederlandse Onderzoekschool voor Astronomie (NOVA)
K. L. Bouman
Harvard-Smithsonian Center for Astrophysics
California Institute of Technology (Caltech)
Harvard University
G. C. Bower
Academia Sinica
M. Bremer
Institut de Radioastronomie Millimétrique (IRAM)
C. D. Brinkerink
Radboud University
Roger Brissenden
Harvard University
Harvard-Smithsonian Center for Astrophysics
Silke Britzen
Max Planck Society
Avery E. Broderick
Perimeter Institute for Theoretical Physics
University of Waterloo
D. Broguière
Institut de Radioastronomie Millimétrique (IRAM)
Thomas Bronzwaer
Radboud University
Do Young Byun
University of Science and Technology (UST)
Korea Astronomy and Space Science Institute
J. E. Carlstrom
University of Chicago
A. Chael
Harvard-Smithsonian Center for Astrophysics
Harvard University
Chi Kwan Chan
University of Arizona
S. Chatterjee
Cornell University
Koushik Chatterjee
University of Amsterdam
Ming Tang Chen
Academia Sinica
Yongjun Chen
Chinese Academy of Sciences
Shanghai Astronomical Observatory
I. Cho
Korea Astronomy and Space Science Institute
University of Science and Technology (UST)
Pierre Christian
University of Arizona
Harvard-Smithsonian Center for Astrophysics
John Conway
Chalmers, Space, Earth and Environment, Onsala Space Observatory
James M. Cordes
Cornell University
G. Crew
Massachusetts Institute of Technology (MIT)
Yuzhu Cui
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
Jordy Davelaar
Radboud University
Mariafelicia De Laurentis
Goethe University Frankfurt
University of Naples Federico II
R. P. Deane
University of Pretoria
Rhodes University
Jessica Dempsey
East Asian Observatory
Gregory Desvignes
Max Planck Society
Jason Dexter
Max Planck Society
S. Doeleman
Harvard-Smithsonian Center for Astrophysics
Harvard University
Ralph P. Eatough
Max Planck Society
H.D. Falcke
Radboud University
V. Fish
Massachusetts Institute of Technology (MIT)
Ed Fomalont
National Radio Astronomy Observatory
R. Fraga-Encinas
Radboud University
P. Friberg
East Asian Observatory
Christian M. Fromm
Goethe University Frankfurt
J. L. Gomez
Institute of Astrophysics of Andalusia (IAA)
Peter Galison
Harvard University
Charles F. Gammie
University of Illinois
Roberto Garcia
Institut de Radioastronomie Millimétrique (IRAM)
Olivier Gentaz
Institut de Radioastronomie Millimétrique (IRAM)
Boris Georgiev
University of Waterloo
C. Goddi
Radboud University
Leiden University
R. Gold
Goethe University Frankfurt
Minfeng Gu
Shanghai Astronomical Observatory
Chinese Academy of Sciences
M. Gurwell
Harvard-Smithsonian Center for Astrophysics
K. Hada
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Michael H. Hecht
Massachusetts Institute of Technology (MIT)
R. Hesper
University of Groningen
Luis C. Ho
Beijing University of Technology
P. T. P. Ho
National Taiwan University
Mareki Honma
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Chih Wei L. Huang
National Taiwan University
Lei Huang
Chinese Academy of Sciences
Shanghai Astronomical Observatory
D. Hughes
National Institute of Astrophysics, Optics and Electronics
Shiro Ikeda
National Astronomical Observatory of Japan
The Institute of Statistical Mathematics
The Graduate University for Advanced Studies (SOKENDAI)
University of Tokyo
Makoto Inoue
National Taiwan University
S. Issaoun
Radboud University
David J. James
Harvard-Smithsonian Center for Astrophysics
Harvard University
Buell T. Jannuzi
University of Arizona
M. Janßen
Radboud University
Britton Jeter
University of Waterloo
Wu Jiang
Shanghai Astronomical Observatory
Michael D. Johnson
Harvard University
Harvard-Smithsonian Center for Astrophysics
S.G. Jorstad
Saint Petersburg State University - Spsu
Boston University
Taehyun Jung
Korea Astronomy and Space Science Institute
University of Science and Technology (UST)
Mansour Karami
University of Waterloo
Perimeter Institute for Theoretical Physics
R. Karuppusamy
Max Planck Society
Tomohisa Kawashima
National Astronomical Observatory of Japan
G. Keating
Harvard-Smithsonian Center for Astrophysics
M. M. Kettenis
Joint Institute for VLBI in Europe (JIVE)
Jae Young Kim
Max Planck Society
Junhan Kim
University of Arizona
Jongsoo Kim
Korea Astronomy and Space Science Institute
M. Kino
Kogakuin University of Technology and Engineering
National Astronomical Observatory of Japan
Jun Yi Koay
National Taiwan University
Patrick M. Koch
National Taiwan University
Shoko Koyama
National Taiwan University
M. Kramer
Max Planck Society
C. Kramer
Institut de Radioastronomie Millimétrique (IRAM)
T.P. Krichbaum
Max Planck Society
Cheng Yu Kuo
National Sun Yat-Sen University
Tod R. Lauer
National Optical Astronomy Observatory
Sang Sung Lee
Korea Astronomy and Space Science Institute
Yan Rong Li
Chinese Academy of Sciences
Zhiyuan Li
Nanjing University
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 875 1 L2Subject Categories
Aerospace Engineering
Astronomy, Astrophysics and Cosmology
DOI
10.3847/2041-8213/ab0c96