The Space multi-band Variable Object Monitor (SVOM) is a proposed Chinese astronomical satellite, dedicated to the detection, localization and measurement of the gamma-ray bursts (GRBs) on the cosmological scale. An efficient algorithm is developed for the purpose of onboard star extraction from the CCD images obtained with the Visible Telescope (VT) on board SVOM. The CCD pixel coordinates of the reference stars will be used to refine the astronomical position of the satellite, which will facilitate trigger rapid ground-based follow-up obsevations of the GRBs. In this algorithm, the image is divided into a number of grid cells and the "global" pixel-value maximum within each cell is taken as the first-guess position of a "bright" star. The correct center postion of a star is then computed using a simple iterative method. Applying two additional strategies, i.e., scanning the image only by even (or odd) lines or in a black-white chess board mode, are proposed to further reduce the time to extract the stars. To examine the efficiency of the above aglorithms, we applied them to the experimental images obtained with a ground-based telescope. We find that the accuracy of the astronomical positioning achieved by our method is comparable to that derived by using the conventional star-extraction method, while the former needs CPU time about 25 times less than the latter. This will significantly improve the performance of the SVOM VT mission.
The coded mask of the ECLAIRs telescope onboard the SVOM space mission
Université Paris Cité, CNRS, Astroparticule et Cosmologie（巴黎西岱大学，法国国家科学研究中心，粒子与宇宙学）；CEA Paris-Saclay, Institut de Recherche sur les lois Fondamentales de l’Univers（巴黎萨克雷原子能委员会，基础定律研究所）；CNES（法国国家空间研究中心）
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Innovation Academy for Microsatellites, Chinese Academy of Science（中国科学院微小卫星创新研究院）；Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences（中国科学院西安光学精密机械研究所）
The SVOM mission under development will carry various instruments, and in particular the coded-mask telescope ECLAIRs, with a large field of view of about 2 sr, operating in the 4--150 keV energy band, whose goal is to detect high energy transients such as gamma-ray bursts. The trigger software onboard ECLAIRs will search for new hard X-ray sources appearing in the sky, as well as peculiar behaviour (e.g. strong outbursts) from known sources, in order to repoint the satellite to perform follow-up observations with its onboard narrow field of view instruments. The presence of known X-ray source…
CEA Paris-Saclay, Institut de Recherche sur les lois Fondamentales de l’Univers（法国原子能和替代能源委员会巴黎萨克雷中心基础定律研究所）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所粒子天体物理重点实验室）；Aix Marseille Université, CNRS, CNES, LAM（艾克斯-马赛大学）；IRAP, Université de Toulouse, CNRS, CNES（图卢兹大学）；Université Paris Cité, CNRS, CEA, Astroparticule et Cosmologie（巴黎西岱大学）；Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris（索邦大学）
The data analysis pipeline for the Microchannel X-ray Telescope on board the SVOM mission
Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS（斯特拉斯堡天文台，斯特拉斯堡大学，法国国家科学研究中心）；AIM-CEA/DRF/Irfu/Departement d’Astrophysique, CNRS, Universite Paris-Saclay, Universite Paris Cite（天体物理研究所，法国国家科学研究中心，巴黎萨克雷大学，巴黎西岱大学）；Centre National d’Etudes Spatiales, Centre spatial de Toulouse（法国国家空间研究中心，图卢兹航天中心）
The Microchannel X-ray Telescope on board the SVOM mission: in-flight scientific performance
AIM-CEA/DRF/Irfu/Departement d’Astrophysique, CNRS, Universite Paris-Saclay, Universite Paris Cite（天体物理学与核物理研究所，法国国家科学研究中心，巴黎萨克雷大学，巴黎 Cité 大学）；Centre National d’Etudes Spatiales, Centre spatial de Toulouse（法国国家空间研究中心，图卢兹航天中心）；Space Park Leicester, University of Leicester（莱斯特大学，莱斯特太空公园）；College of Science and Engineering, School of Mathematics and Physics, Kanazawa University（金泽大学，理学院，数学与物理系）
SVOM/VT: Overview of data processing and GRB identifications with X-band data
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Institute for Frontier in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿交叉科学研究院）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理学院）
The SVOM mission under development will carry four instruments, and in particular the coded-mask telescope named ECLAIRs, with a large field of view of about 2 sr, operating in the 4-150 keV energy band. The trigger software on board ECLAIRs will search for high-energy transients such as gamma-ray bursts and peculiar behaviour (e.g. strong outbursts) from known X-ray sources, in order to repoint the satellite to perform follow-up observations with the onboard narrow field of view instruments. The image trigger, one of the two algorithms implemented in the software on board ECLAIRs, produces im…
Sorbonne Université（索邦大学）；CNRS（法国国家科学研究中心）；Institut d’Astrophysique de Paris（巴黎天体物理研究所）；Institut Universitaire de France（法兰西学院）；CEA Paris-Saclay（巴黎萨克雷原子能委员会）；IRAP（天体物理学研究研究所）；Université de Toulouse（图卢兹大学）；CNES（法国国家空间研究中心）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；LUX, Observatoire de Paris, Université PSL（巴黎天文台LUX实验室，PSL大学）；The Hong Kong Institute for Astronomy and Astrophysics, the University of Hong Kong（香港大学香港天体物理研究所）；Department of Physics, the University of Hong Kong（香港大学物理系）；Laboratoire Univers et Particules de Montpellier（蒙彼利埃宇宙与粒子实验室）；Université Montpellier（蒙彼利埃大学）
本文报告 SVOM 卫星在轨测试期间对数十个伽马射线暴的早期观测结果，展示了其探测和全面表征各类 GRB 的能力。
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）
SVOM/VT: Instrument Overview, Science Objectives, and First-Year Performance
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences（中国科学院西安光学精密机械研究所）
A Micro-Channel Plate (MCP) is a widely used component for counting particles in space. Using the background counts of MCPs on Mars Express and Venus Express orbiters operated over 17 years and 8 years, respectively, we investigate the galactic cosmic ray (GCR) characteristics in the inner solar system. The MCP background counts at Mars and Venus on a solar cycle time scale exhibit clear anti-correlation to the sunspot number. We conclude that the measured MCP background contain the GCR information. The GCR characteristics measured using the MCP background at Mars show features that are consis…
Hayabusa2, a Japanese sample-return mission to a C-type asteroid, arrived at its target 162173 Ryugu in June 2018. The optical navigation cameras (ONC-T, ONC-W1, ONC-W2) successfully obtained numerous images of Ryugu. ONC-T is a telescopic framing camera with a charge-coupled device (CCD), has seven filter bands in ultraviolet, visible and near infrared wavelength ranges, and were used to map the spectral distribution of the Ryugu surface. Since the locations of a target seen in ONC-T images are slightly different among different wavelength images in one multi-band observation sequence due to …
