The science case and challenges of space-borne sub-millimeter interferometry
Creators: name: Gurvits, Leonid I.
name: Paragi, Zsolt
name: Amils, Ricardo I.
name: van Bemmel, Ilse
name: Boven, Paul
name: Casasola, Viviana
name: Conway, John
name: Davelaar, Jordy
name: Díez-González, M. Carmen
name: Falcke, Heino
name: Fender, Rob
name: Frey, Sándor
name: Fromm, Christian M.
name: Gallego-Puyol, Juan D.
name: García-Miró, Cristina
name: Garrett, Michael A.
name: Giroletti, Marcello
name: Goddi, Ciriaco
name: Gómez, José L.
name: van der Gucht, Jeffrey
name: Guirado, José Carlos
name: Haiman, Zoltán
name: Helmich, Frank
name: Hudson, Ben
name: Humphreys, Elizabeth
name: Impellizzeri, Violette
name: Janssen, Michael
name: Johnson, Michael D.
name: Kovalev, Yuri Y.
name: Kramer, Michael
name: Lindqvist, Michael
name: Linz, Hendrik
name: Liuzzo, Elisabetta
name: Lobanov, Andrei P.
name: López-Fernández, Isaac
name: Malo-Gómez, Inmaculada
name: Masania, Kunal
name: Mizuno, Yosuke
name: Plavin, Alexander V.
name: Rajan, Raj T.
name: Rezzolla, Luciano
name: Roelofs, Freek
name: Ros, Eduardo
name: Rygl, Kazi L. J.
name: Savolainen, Tuomas
name: Schuster, Karl
name: Venturi, Tiziana
name: Verkouter, Marjolein
name: de Vicente, Pablo
name: Visser, Pieter N. A. M.
name: Wiedner, Martina C.
name: Wielgus, Maciek
name: Wiik, Kaj
name: Zensus, J. Anton
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Ultra-high angular resolution in astronomy has always been an important vehicle for making fundamental discoveries. Recent results in direct imaging of the vicinity of the supermassive black hole in the nucleus of the radio galaxy M87 by the millimeter VLBI system Event Horizon Telescope and various pioneering results of the Space VLBI mission RadioAstron provided new momentum in high angular resolution astrophysics. In both mentioned cases, the angular resolution reached the values of about 10-20 microrcseconds. Further developments toward at least an order of magnitude "sharper" values are dictated by the needs of astrophysical studies and can only be achieved by placing millimeter and submillimeter wavelength interferometric systems in space. A concept of such the system, called Terahertz Exploration and Zooming-in for Astrophysics (THEZA), has been proposed in the framework of the ESA Call for White Papers for the Voayage 2050 long term plan in 2019. In the current paper we discuss several approaches for addressing technological challenges of the THEZA concept. In particular, we consider a novel configuration of a space-borne millimeter/sub-millimeter antenna which might resolve several bottlenecks in creating large precise mechanical structures. The paper also presents an overview of prospective space-qualified technologies of low-noise analogue front-end instrumentation for millimeter/sub-millimeter telescopes, data handling and processing. The paper briefly discusses approaches to the interferometric baseline state vector determination and synchronisation and heterodyning system. In combination with the original ESA Voyage 2050 White Paper, the current work sharpens the case for the next generation microarcsceond-level imaging instruments and provides starting points for further in-depth technology trade-off studies.
description: The paper on 29 pages contains 12 figures, accepted for publication in Acta Astronautica, based on the presentation at the 72nd IAC, Dubai, UAE, October 2021