SKA低频成像系统在中国SKA区域中心的部署

平方公里阵列(Square Kilometre Array, SKA)将成为世界上最大的综合孔径射电望远镜.凭借其高分辨率、超高灵敏度和超快巡天速度, SKA能以前所未有的细节探索宇宙.连续谱巡天是SKA的几个主要观测模式之一,为理解和认识射电天空奠定基础. SKA探路者设备已经运行了几年,积累了丰富的巡天观测数据.中国天文学家正在为中国SKA区域中心(China SKA Regional Centre, CSRC)的建设进行积极的准备,已经完成了原型机.本文详细介绍了在CSRC原型机中部署SKA低频数据处理系统的进展.默奇森宽场阵列(Murchison Wide-field Array, MWA)是SKA低频阵列的先导项目.我们使用MWA的观测数据来验证成像管线系统的部署并测试其正确性. CSRC原型机的数据处理结果与已发表的结果一致,表明在CSRC原型机上部署开发的并行数据处理系统取得了巨大成功.而且,该原型机的灵活适配性和可扩展性使其可以轻松扩展,支持未来SKA第一阶段试运行期间的大规模连续谱成像实验.这些经验将有助于改善成像管线系统,并有助于完善CSRC.

Deployment of SKA low frequency imaging system in China SKA Regional Centre

The Square Kilometre Array(SKA) will be the largest synthesized radio telescope in the world. Thanks to its high resolution, ultra-high sensitivity and super fast survey speed, the SKA can explore the Universe with unprecedented details.The continuum survey, being one of the key observational modes of the SKA, establishes the basis of fundamental understandings of the radio sky. SKA pathfinders have been operational for several years and accumulated rich survey data.Chinese astronomers are enthusiastically preparing for the construction of China SKA Regional Centre(CSRC), and have already completed the prototype. The present paper introduces the detailed implementation of the SKA low-frequency data processing system in the CSRC prototype. The continuum survey data observed by the Murchison Widefield Array(MWA), the SKA-low precursor, were used to verify the pipeline deployment and test the correctness. The data processing results are consistent with the published one, suggesting that the parallel data processing developed in the CSRC prototype is a great success. The flexibility and scalability of the prototype allows it to easily expand for future large-scale continuum imaging survey during the commissioning phase of the SKA. The valuable experience gained in these experiments is helpful for future improving the imaging pipeline, and developing the CSRC.