Browsing by Author "Linz, Hendrik"

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  • The Large Interferometer For Exoplanets (LIFE): a space mission for mid-infrared nulling interferometry
    (2024-08-28) Glauser, Adrian M.; Quanz, Sascha P.; Hansen, Jonah; Dannert, Felix; Ireland, Michael; Linz, Hendrik; Absil, Olivier; Alei, Eleonora; Angerhausen, Daniel; Birbacher, Thomas; Defrère, Denis; Fortier, Andrea; Huber, Philipp A.; Kammerer, Jens; Laugier, Romain; Lichtenberg, Tim; Noack, Lena; Ranganathan, Mohanakrishna; Rugheimer, Sarah; Airapetian, Vladimir; Alibert, Yann; Amado, Pedro J.; Anger, Marius
     A4 Artikkeli konferenssijulkaisussa
    The Large Interferometer For Exoplanets (LIFE) is a proposed space mission that enables the spectral characterization of the thermal emission of exoplanets in the solar neighborhood. The mission is designed to search for global atmospheric biosignatures on dozens of temperate terrestrial exoplanets and it will naturally investigate the diversity of other worlds. Here, we review the status of the mission concept, discuss the key mission parameters, and outline the trade-offs related to the mission’s architecture. In preparation for an upcoming concept study, we define a mission baseline based on a free-formation flying constellation of a double Bracewell nulling interferometer that consists of 4 collectors and a central beam-combiner spacecraft. The interferometric baselines are between 10–600m, and the estimated diameters of the collectors are at least 2m (but will depend on the total achievable instrument throughput). The spectral required wavelength range is 6–16μm (with a goal of 4–18.5μm), hence cryogenic temperatures are needed both for the collectors and the beam combiners. One of the key challenges is the required deep, stable, and broad-band nulling performance while maintaining a high system throughput for the planet signal. Among many ongoing or needed technology development activities, the demonstration of the measurement principle under cryogenic conditions is fundamentally important for LIFE.
  • The science case and challenges of space-borne sub-millimeter interferometry
    (2022-07) Gurvits, Leonid I.; Paragi, Zsolt; Amils, Ricardo I.; van Bemmel, Ilse; Boven, Paul; Casasola, Viviana; Conway, John; Davelaar, Jordy; Díez-González, M. Carmen; Falcke, Heino; Fender, Rob; Frey, Sándor; Fromm, Christian M.; Gallego-Puyol, Juan D.; García-Miró, Cristina; Garrett, Michael A.; Giroletti, Marcello; Goddi, Ciriaco; Gómez, José L.; van der Gucht, Jeffrey; Guirado, José Carlos; Haiman, Zoltán; Helmich, Frank; Hudson, Ben; Humphreys, Elizabeth; Impellizzeri, Violette; Janssen, Michael; Johnson, Michael D.; Kovalev, Yuri Y.; Kramer, Michael; Lindqvist, Michael; Linz, Hendrik; Liuzzo, Elisabetta; Lobanov, Andrei P.; López-Fernández, Isaac; Malo-Gómez, Inmaculada; Masania, Kunal; Mizuno, Yosuke; Plavin, Alexander V.; Rajan, Raj T.; Rezzolla, Luciano; Roelofs, Freek; Ros, Eduardo; Rygl, Kazi L. J.; Savolainen, Tuomas; Schuster, Karl; Venturi, Tiziana; Verkouter, Marjolein; de Vicente, Pablo; Visser, Pieter N. A. M.; Wiedner, Martina C.; Wielgus, Maciek; Wiik, Kaj; Zensus, J. Anton
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    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 microarcseconds (0.05–0.1 nanoradian). Further developments towards at least an order of magnitude “sharper” values, at the level of 1 microarcsecond are dictated by the needs of advanced astrophysical studies. The paper emphasis that these higher values 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, has been proposed in the framework of the ESA Call for White Papers for the Voyage 2050 long term plan in 2019. In the current paper we present new science objectives for such the concept based on recent results in studies of active galactic nuclei and supermassive black holes. We also discuss several approaches for addressing technological challenges of creating a millimeter/sub-millimeter wavelength interferometric system in space. 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 instrumentation is another key technological component of a sub-millimeter Space VLBI system. Requirements and possible implementation options for this instrumentation are described as an extrapolation of the current state-of-the-art Earth-based VLBI data transport and processing instrumentation. The paper also briefly discusses approaches to the interferometric baseline state vector determination and synchronisation and heterodyning system. The technology-oriented sections of the paper do not aim at presenting a complete set of technological solutions for sub-millimeter (terahertz) space-borne interferometers. Rather, in combination with the original ESA Voyage 2050 White Paper, it sharpens the case for the next generation microarcsecond-level imaging instruments and provides starting points for further in-depth technology trade-off studies.
  • THEZA: TeraHertz Exploration and Zooming-in for Astrophysics: An ESA Voyage 2050 White Paper
    (2021-06) Gurvits, Leonid I.; Paragi, Zsolt; Casasola, Viviana; Conway, John; Davelaar, Jordy; Falcke, Heino; Fender, Rob; Frey, Sándor; Fromm, Christian M.; Garcia Miro, Cristina; Garrett, Michael A.; Giroletti, Marcello; Goddi, Ciriaco; Gaomez, Jose-Luis; van der Gucht, Jeffrey; Guirado, Jose Carlos; Haiman, Zoltaan; Helmich, Frank; Humphreys, Elizabeth; Impellizzeri, Violette; Kramer, Michael; Lindqvist, Michael; Linz, Hendrik; Liuzzo, Elisabetta; Lobanov, Andrei P.; Mizuno, Yosuke; Rezzolla, Luciano; Roelofs, Freek; Ros, Eduardo; Rygl, Kazi L. J.; Savolainen, Tuomas; Schuster, Karl; Venturi, Tiziana; Wiedner, Martina; Zensus, J. Anton
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    This paper presents the ESA Voyage 2050 White Paper for a concept of TeraHertz Exploration and Zooming-in for Astrophysics (THEZA). It addresses the science case and some implementation issues of a space-borne radio interferometric system for ultra-sharp imaging of celestial radio sources at the level of angular resolution down to (sub-) microarcseconds. THEZA focuses at millimetre and sub-millimetre wavelengths (frequencies above ∼300 GHz), but allows for science operations at longer wavelengths too. The THEZA concept science rationale is focused on the physics of spacetime in the vicinity of supermassive black holes as the leading science driver. The main aim of the concept is to facilitate a major leap by providing researchers with orders of magnitude improvements in the resolution and dynamic range in direct imaging studies of the most exotic objects in the Universe, black holes. The concept will open up a sizeable range of hitherto unreachable parameters of observational astrophysics. It unifies two major lines of development of space-borne radio astronomy of the past decades: Space VLBI (Very Long Baseline Interferometry) and mm- and sub-mm astrophysical studies with “single dish” instruments. It also builds upon the recent success of the Earth-based Event Horizon Telescope (EHT) – the first-ever direct image of a shadow of the super-massive black hole in the centre of the galaxy M87. As an amalgam of these three major areas of modern observational astrophysics, THEZA aims at facilitating a breakthrough in high-resolution high image quality studies in the millimetre and sub-millimetre domain of the electromagnetic spectrum.