Mock Observations for the CSST Mission: Main Surveys--the Stray Light

TL;DR

This paper presents an analytical model for the CSST that quickly estimates stray-light levels from various sources, improving image quality assessment and observation planning.

Contribution

The authors developed a novel analytical model to rapidly simulate stray-light backgrounds considering multiple sources and effects for the CSST.

Findings

Model accurately estimates stray-light levels under complex conditions.

Enables efficient image simulation and observation scheduling.

Supports improved telescope performance assessment.

Abstract

Stray light significantly influences the detection capabilities of astronomical telescopes. The actual stray-light level during observations depends not only on the telescope's inherent stray-light suppression capability but also on its operational orbit conditions. Accurate estimation of stray-light levels is crucial for assessing image quality and performing realistic scientific simulations. To rapidly estimate stray-light levels under realistic, complex operational conditions, we developed an analytical model tailored to the China Space Station Telescope (CSST). Our model simulates stray-light backgrounds generated by off-field sources such as moonlight, starlight, and earthshine, incorporating the effects of zodiacal light, as well as scattering and ghost images induced by bright in-field stars. The proposed method allows quick and accurate evaluation of stray-light conditions, facilitating both image simulation and observational scheduling.