Asgard/NOTT: L-band nulling interferometry at the VLTI. II. Warm optical design and injection system
Germain Garreau, Azzurra Bigioli, Romain Laugier, Gert Raskin, Johan Morren, Jean-Philippe Berger, Colin Dandumont, Harry-Dean Kenchington Goldsmith, Simon Gros… 展开作者
Germain Garreau, Azzurra Bigioli, Romain Laugier, Gert Raskin, Johan Morren, Jean-Philippe Berger, Colin Dandumont, Harry-Dean Kenchington Goldsmith, Simon Gross, Michael Ireland, Lucas Labadie, Jérôme Loicq, Stephen Madden, Guillermo Martin, Marc-Antoine Martinod, Alexandra Mazzoli, Ahmed Sanny, Hancheng Shao, Kunlun Yan, Denis Defrère
备注：
Accepted for publication in JATIS. 23 pages, 11 figures, 8 tables
发表信息：
J. Astron. Telesc. Instrum. Syst. 10(1), 015002 (2024)
Asgard/NOTT (previously Hi-5) is a European Research Council (ERC)-funded project hosted at KU Leuven and a new visitor instrument for the Very Large Telescope Interferometer (VLTI). Its primary goal is to image the snow line region around young stars using nulling interferometry in the L-band (3.5 to 4.0)$μ$m, where the contrast between exoplanets and their host stars is advantageous. The breakthrough is the use of a photonic beam combiner, which only recently allowed the required theoretical raw contrast of $10^{-3}$ in this spectral range. Nulling interferometry observations of exoplanets also require a high degree of balancing between the four pupils of the VLTI in terms of intensity, phase, and polarization. The injection into the beam combiner and the requirements of nulling interferometry are driving the design of the warm optics and the injection system. The optical design up to the beam combiner is presented. It offers a technical solution to efficiently couple the light from the VLTI into the beam combiner. During the coupling, the objective is to limit throughput losses to 5% of the best expected efficiency for the injection. To achieve this, a list of different loss sources is considered with their respective impact on the injection efficiency. Solutions are also proposed to meet the requirements on beam balancing for intensity, phase, and polarization. The different properties of the design are listed, including the optics used, their alignment and tolerances, and their impact on the instrumental performances in terms of throughput and null depth. The performance evaluation gives an expected throughput loss of less than <6.4% of the best efficiency for the injection and a null depth of $\sim2.10^{-3}$, mainly from optical path delay errors outside the scope of this work.
Context: NOTT (formerly Hi-5) is a new high-contrast L' band (3.5-4.0 \textmu m) beam combiner for the VLTI with the ambitious goal to be sensitive to young giant exoplanets down to 5 mas separation around nearby stars. The performance of nulling interferometers in these wavelengths is affected both by fundamental noise from the background and by the contributions of instrumental noises. This motivates the development of end-to-end simulations to optimize these instruments. Aims: To enable the performance evaluation and inform the design of such instruments on the current and future infrastruc…
Performance Analysis of the Asgard/NOTT Nulling Interferometer: Optimizing Observing Modes for High-contrast Detection
The University of Arizona（亚利桑那大学）；Large Binocular Telescope Observatory, The University of Arizona（大双筒望远镜天文台，亚利桑那大学）；KU Leuven（荷语鲁汶大学）；Université Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学，法国国家科学研究中心，天体物理与行星学研究所）；ETH Zürich, Institute for Particle Physics & Astrophysics（苏黎世联邦理工学院，粒子物理与天体物理研究所）；European Southern Observatory（欧洲南方天文台）；Australian National University（澳大利亚国立大学）；Ghent University（根特大学）；University of Exeter（埃克塞特大学）；Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸大学，蔚蓝海岸天文台，法国国家科学研究中心，拉格朗日实验室）；University of Kiel（基尔大学）
Asgard/NOTT: L-band nulling interferometry at the VLTI -- III. The mid-infrared integrated optics beam combiner for NOTT
I. Physikalisches Institut der Universität zu Köln（科隆大学第一物理研究所）；Department of Physics & Astronomy, University of California, Los Angeles（加州大学洛杉矶分校物理与天文学系）；Institute of Astronomy, KU Leuven（鲁汶大学天体物理研究所）
Status and performance of the Asgard/NOTT cold nulling camera
KU Leuven（荷语鲁汶大学）；Fornax（福纳克斯研究所）；University of Liège（列日大学）；Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences（孔科利天文台，匈牙利研究与教育网络天文学与地球科学研究中心）；Australian National University（澳大利亚国立大学）；Delft University of Technology（代尔夫特理工大学）；University of Arizona（亚利桑那大学）；University of Exeter（埃克塞特大学）；Université Côte d’Azur（蔚蓝海岸大学）；European Organisation for Astronomical Research in the Southern Hemisphere（欧洲南方天文台）；Large Binocular Telescope Observatory（大型双筒望远镜天文台）
Hi-5 is the L'-band (3.5-4.0 $μ$m) high-contrast imager of Asgard, an instrument suite in preparation for the visitor focus of the VLTI. The system is optimized for high-contrast and high-sensitivity imaging within the diffraction limit of a single UT/AT telescope. It is designed as a double-Bracewell nulling instrument producing spectrally-dispersed (R=20, 400, or 2000) complementary nulling outputs and simultaneous photometric outputs for self-calibration purposes. In this paper, we present an update of the project with a particular focus on the overall architecture, opto-mechanical design o…
Asgard/NOTT: Cryogenic characterization of the mid-infrared chip
ETH Zürich（苏黎世联邦理工学院）；KU Leuven（荷语鲁汶大学）；Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸大学、蔚蓝海岸天文台、法国国家科学研究中心、拉格朗日实验室）；The University of Arizona（亚利桑那大学）；Large Binocular Telescope Observatory（大型双筒望远镜天文台）；Macquarie University（麦考瑞大学）；European Southern Observatory（欧洲南方天文台）；Australian National University（澳大利亚国立大学）；Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences（孔科利天文台，匈牙利研究与教育网络天文学与地球科学研究中心）；University of Exeter（埃克塞特大学）；Universität zu Köln（科隆大学）；STAR Institute, University of Liège（列日大学STAR研究所）
Asgard/NOTT: Status of laboratory nulling performance
ETH Zürich, Institute for Particle Physics & Astrophysics（苏黎世联邦理工学院粒子物理与天体物理研究所）；Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸大学、蔚蓝海岸天文台、法国国家科学研究中心拉格朗日实验室）；European Southern Observatory（欧洲南方天文台）；Large Binocular Telescope Observatory, The University of Arizona（大型双筒望远镜天文台，亚利桑那大学）
The Very Large Telescope Interferometer is one of the most proficient observatories in the world for high angular resolution. Since its first observations, it has hosted several interferometric instruments operating in various bandwidths in the infrared. As a result, the VLTI has yielded countless discoveries and technological breakthroughs. Here, we introduce a new concept for the VLTI, Asgard: an instrumental suite comprised of four natively collaborating instruments: BIFROST, a combiner whose main science case is studying the formation processes and properties of stellar and planetary syste…
Pushing high angular resolution and high contrast observations on the VLTI from Y to L band with the Asgard instrumental suite: integration status and plans
Pushing high angular resolution and high contrast observations on the VLTI from Y to L band with the Asgard instrumental suite: integration status and plans
Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸大学、蔚蓝海岸天文台、法国国家科学研究中心、拉格朗日实验室）；Research School of Astronomy and Astrophysics, College of Science, Australian National University（澳大利亚国立大学理学院天文学与天体物理学家研究学院）；School of Physics and Astronomy, University of Exeter（埃克塞特大学物理与天文学院）；Institute of Astronomy, KU Leuven（鲁汶大学天文学研究所）；Space sciences, Technologies & Astrophysics Research (STAR) Institute, University of Liège（列日大学空间科学与技术天体物理研究（STAR）研究所）；Institute for Particle Physics and Astrophysics, ETH Zurich（苏黎世联邦理工学院粒子物理与天体物理研究所）；Department of Astronomy and Steward Observatory（天文学系及斯图尔德天文台）；Large Binocular Telescope Observatory（大型双筒望远镜天文台）；I. Physikalisches Institut, Universität zu Köln（科隆大学第一物理研究所）；European Organisation for Astronomical Research in the Southern Hemisphere（欧洲南方天文台）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；Konkoly Observatory（孔科利天文台）；University of California, Los Angeles（加州大学洛杉矶分校）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；Australian Astronomical Optics & School of Mathematical and Physical Sciences, Macquarie University（麦考瑞大学澳大利亚天文光学部及数学与物理科学学院）；Research Software Engineering, NUIT, Newcastle University（纽卡斯尔大学NUIT研究软件工程）
Seidr update: photonic 'black magic' for high-contrast interferometry using kernel-nulling and photonic lanterns
University of Sydney（悉尼大学）；Observatoire de la Cote d’Azur, Université Côte d’Azur（蔚蓝海岸天文台，蔚蓝海岸大学）；Australian National University（澳大利亚国立大学）；University of Exeter（埃克塞特大学）；Leiden University（莱顿大学）
Achieving efficient broadband spatial filtering for LIFE: status and plan
ETH Zürich（苏黎世联邦理工学院）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；Sydney Institute for Astronomy, School of Physics, University of Sydney（悉尼大学物理学院天体物理研究所）；Research School of Astronomy & Astrophysics, Australian National University（澳大利亚国立大学天文与天体物理研究学院）
