A Roadmap towards a Space-based Radio Telescope for Ultra-Low Frequency Radio Astronomy
M. J. Bentum, M. K. Verma, R. T. Rajan, A. -J. Boonstra, C. J. M. Verhoeven, E. K. A. Gill, A. J. van der Veen, H. Falcke, M. Klein Wolt, B. Monna, S. Engelen, … 展开作者
M. J. Bentum, M. K. Verma, R. T. Rajan, A. -J. Boonstra, C. J. M. Verhoeven, E. K. A. Gill, A. J. van der Veen, H. Falcke, M. Klein Wolt, B. Monna, S. Engelen, J. Rotteveel, L. I. Gurvits
The past two decades saw a renewed interest in low frequency radio astronomy, with a particular focus on frequencies above 30 MHz. However, at frequencies below 30 MHz, Earth-based observations are limited due to a combination of severe ionospheric distortions, almost full reflection of radio waves below 10 MHz, solar eruptions and human-made radio frequency interference (RFI). A space or Lunar-based ultra-low-frequency (or ultra-long-wavelength, ULW) array would suffer significantly less from these limitations and hence would open up the last, virtually unexplored frequency domain in the electromagnetic spectrum. A roadmap has been initiated in order to explore the opportunity of building a swarm of satellites to observe at the frequency band below 30 MHz. This roadmap, dubbed Orbiting Low Frequency Antennas for Radio Astronomy (OLFAR), presents a space-based ultra-low frequency radio telescope that will explore the Universe's so-called dark ages, map the interstellar medium, and study planetary and solar bursts in the solar system and search them in other planetary systems. Such a system will comprise of a swarm of hundreds to thousands of satellites, working together as a single aperture synthesis instrument deployed sufficiently far away from Earth to avoid terrestrial RFI. A number of key technologies of OLFAR are still to be developed and proven. The first step in this roadmap is the NCLE (Netherlands China Low Frequency Explorer) experiment launched in May 2018 on the Chinese Chang'e-4 mission. The NCLE payload consists of a three monopole antenna system from which the first data stream is expected in the second half of 2019, which will provide important feedback for future science and technology opportunities. In this paper, the roadmap towards OLFAR, a brief overview of the science opportunities, and the technological and programmatic challenges of the mission are presented.
An Ultra Fast Image Generator (UFig) for wide-field astronomy
模拟的宽视场图像正在成为观测天文学的一个重要组成部分，无论是为新的调查做准备还是测试测量方法。为了有效地探索巨大的参数空间，仿真代码的计算速度是其实现的核心要求。我们介绍了超快速图像生成器（UFig），其目的是将宽场成像模拟带到当前计算能力的极限。我们通过以下方式实现这一目标：（1）星系、恒星和观测条件的模型，虽然简单，但捕捉了逼真模拟所需的关键特征，以及（2）最先进的计算和实现优化。我们提出的UFig的性能，并表明它是快于现有的公共模拟代码的几个数量级。它使我们能够比SExtractor更快地生成图像来分析它们。例如，它可以在30秒内在笔记本电脑上模拟一个典型的0.25 deg^2斯巴鲁SuprimeCam图像（10k x 8k像素），5 σ极限星等为R=26，产生一个星系的平均模拟时间为30微秒。该代码是端到端仿真代码的补充，可用作依赖于仿真的观测方法的快速核心组件。
AstroLLaVA: towards the unification of astronomical data and natural language
UniverseTBD；Indian Institute of Technology Delhi（印度理工学院德里分校）；Intelligent Internet Inc.（Intelligent Internet公司）；University of Florence（佛罗伦萨大学）；Instituto de Astrofísica de Canarias (IAC)（加那利群岛天体物理学研究所）；Observatoire de Paris（巴黎天文台）；PSL University（巴黎文理研究大学）；Université Paris-Cité（巴黎城市大学）；ANU RSAA（澳大利亚国立大学天体物理学与天体生物学研究学院）；European Space Agency（欧洲空间局）；IRISA（IRISA研究所）；Université Bretagne Sud（南布列塔尼大学）；ANU School of Computing（澳大利亚国立大学计算机学院）
Distributed image reconstruction for very large arrays in radio astronomy
Laboratoire Joseph-Louis Lagrange（约瑟夫-路易·拉格朗日实验室）；Université de Nice Sophia-Antipolis（尼斯索菲亚·安提波利斯大学）；CNRS（法国国家科学研究中心）；Observatoire de la Côte d’Azur（蔚蓝海岸天文台）
Photonic Integrated Circuits for the Habitable Worlds Observatory: Science Drivers, Material Platforms, Arrayed-Waveguide Spectrographs, and a Space-Qualification Roadmap
Leibniz Institute for Astrophysics Potsdam (AIP)（波茨坦莱布尼茨天体物理研究所）
