Akiyama, K;
Alberdi, A;
Alef, W;
Asada, K;
Azulay, R;
Baczko, A-K;
Ball, D;
... Ziurys, L; + view all
(2019)
First M87 Event Horizon Telescope Results. II. Array and Instrumentation.
The Astrophysical Journal Letters
, 875
, Article L2. 10.3847/2041-8213/ab0c96.
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Abstract
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.
| Type: | Article |
|---|---|
| Title: | First M87 Event Horizon Telescope Results. II. Array and Instrumentation |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/2041-8213/ab0c96 |
| Publisher version: | https://doi.org/10.3847/2041-8213/ab0c96 |
| Language: | English |
| Additional information: | Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. https://creativecommons.org/licenses/by/3.0/ |
| Keywords: | black hole physics – galaxies: individual (M87) – Galaxy: center – gravitational lensing: strong – instrumentation: interferometers – techniques: high angular resolution |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10073500 |
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