中法天关项目围绕两大科学课题开展积极合作：1）暂现源天空和高能天体物理；2）银河系及河外星系天文学。鉴于中法合作的长期可持续性，该项目将特别针对青年科学家开展坚实的交流合作。

The scientific project is organized around two main science themes “The transient sky and high-energy astrophysics” and “Galactic and extragalactic astronomy”, for which the collaborations are very strong and active. This Sino-French collaboration around a solid exchange program is proposed to structure, in particular for young scientists in view of the long-term sustainability of the collaboration.

暂现源天空和高能天体物理课题的主要任务为：针对SVOM卫星项目，基于自身卫星获取的科学数据以及其他地面望远镜获取的互补数据开展科学探索。这赖于一个庞大的中法合作团队参与其中，特别是青年科学家的加入和培训。通过SVOM和地面望远镜的结合，期待解决伽马射线暴物理、黑洞中子星双星系统起源、星系中心大质量双黑洞物理、超新星对星系化学演化的影响等重要科学问题。

The main task of “The transient sky and high energy astrophysics” is the scientific exploitation of the SVOM mission, both with data acquired by the satellite, and with complementary data acquired with ground-based telescopes. This requires the participation of a large Chinese-French community, among which many younger people which need to be integrated and trained. From the combination of SVOM and ground-based data, we will address the questions of physics of gamma-ray bursts, the origin and frequency of binary systems with black holes or neutron stars, the physics of the massive binary black-holes in the center of galaxies, and the influence of supernovae on the chemical evolution of galaxies.

在银河系及河外星系天文学课题中，中法合作主要涉及两部分：1）针对未来大型巡天项目开展预研，包括SDSS, Gaia, DESI, LAMOST, Euclid, CSST, Mephisto，另一部分则将围绕大型N体模拟和流体力学模拟展开分析。其科学目标是理解星系动力学的精细机制。在该领域的诸多前沿课题上，中法合作在世界范围内处于领先地位，所开展的工作包括利用LAMOST获得星系旋转曲线、测定银河系数百万颗恒星的质量、年龄和化学性质、星际尘埃和消光的全天三位分布等。

        In this field of “Galactic and extragalactic astronomy”, the Sino-French collaboration is two-folded, one part is based on the exploitation and also preparation of large surveys (e.g., SDSS, Gaia, DESI, LAMOST, Euclid, CSST, Mephisto), and the second part is performing large numerical N-body and hydrodynamical simulations. Scientific objectives are to understand the dynamical elaboration of galaxies. In many of the scientific topics, the Sino-French collaboration is a world-wide leader, including for the Galaxy rotation curve acquired with LAMOST, the determinations of masses, ages and chemical properties for millions of Galactic disk stars, the whole-sky three-dimensional distribution of the interstellar dust grains and extinction.

云南大学中国西南天文研究所注重天文学基础研究能力建设以及国际交流合作。目前正在建设或研制中的观测设备包括云南大学50公分测光望远镜阵列、1.6米多通道测光巡天望远镜。作为主要合作方，中国西南天文研究所牵头推动并参与中法天关合作项目，这将显著高云南大学的国际合作水平。考虑到 SVOM 和 Mephisto 巨大的合作潜能，云南大学参与中法天关项目还将有助提升多波段观测对时域天文学的影响力。

        SWIFAR-YNU is devoted to the national astronomy research capability development and international collaboration. Observing facilities currently under construction or development include the Yunnan University 50cm Photometric Telescope Array, the 1.6m Multi-Channel Photometric Survey Telescope (Mephisto). As the main collaborative party, SWIFAR-YNU takes the lead in promoting the Sino-French Tianguan Project. Joining in Sino-French Tianguan Project as a full institutional member for Yunnan University is an excellent opportunity to enhance the international collaborations of Yunnan University. Considering the potential synergy between SVOM and Mephisto, this can also promote the scientific influence of the multiwavelength observation in time domain astronomy.