Mock Observations for the CSST Mission: Integral Field Spectrograph--Instrument Simulation
Authors
Zhao-Jun Yan
Jun Yin
Lei Hao
Shi-Yin Shen
Wei Chen
Shuai Feng
Yi-Fei Xiong
Chun Xu
Xin-Rong Wen
Lin Lin
Chao Liu
Lin Long
Zhen-Lei Chen
Mao-Chun Wu
Xiao-Bo Li
Zhang Ban
Xun Yang
Yu-Xi Jiang
Guo-Liang Li
Ke-Xin Li
Jian-Jun Chen
Nan Li
Cheng-Liang Wei
Lei Wang
Bai-Chuan Ren
Jun Wei
Jing Tang
Ran Li
Abstract
The Chinese Space Station Survey Telescope (CSST) is a next-generation Stage-IV facility renowned for its wide field of view, high image quality, and multi-band observational capabilities. Among the five instruments onboard the CSST, the Integral Field Spectrograph (IFS) offers the unique ability to simultaneously capture spatial and spectral information across a field of view of no less than $6^{''}\times6^{''}$. Key advantages of the IFS include a high spatial resolution of $0.2^{''}$ and a broad spectral coverage from 350 to 1000 nm, making it an ideal instrument for studying physical processes in the vicinity of supermassive black holes within galaxies. To more accurately assess the technical and scientific performance of the CSST-IFS, it is essential to develop a simulation tool that incorporates realistic effects from all optical components. Such a simulation will form an integral part of the CSST-IFS data and pipeline system, enabling the development of the data reduction pipeline well ahead of actual observations. This paper presents an end-to-end simulation workflow for the CSST-IFS, incorporating a wide range of instrumental effects that may influence its spectral and imaging performance. The simulation accounts for optical diffraction effects introduced by all components, such as image slicers and slit array, as well as sub-pixel effects from gratings. It also includes various detector noises, frame-shifting effects, and charge-transfer inefficiency. Real observational conditions--such as target Doppler shift, cosmic rays, and other in-orbit operational effects--are also considered. We describe the technical implementation of the simulation and present results that quantitatively characterize key instrument parameters.
