WST仪器曝光时间计算器：从源到探测器的多模式光谱仪性能全模拟
WST instrument Exposure Time Calculator: full simulation of multi-mode spectrograph performance from source to detector
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中文总结 AI 辅助
该研究为处于概念阶段的广域光谱望远镜（WST）开发了名为pyetc_wst的曝光时间计算器，可模拟其三种模式光谱仪性能，支持曝光时间优化与光谱相关输出，为WST巡天设计提供工具支撑。
中文摘要 AI 辅助
我们介绍为广域光谱望远镜（WST）概念开发的综合曝光时间计算器（ETC）。目前处于概念阶段的WST是下一代大型光谱巡天设施，具备三种互补观测模式：覆盖370-930 nm、分辨率R约4800的积分场光谱仪（IFS）；四个波段、分辨率R约40000的高分辨率多目标光谱仪（MOS-HR）；四个通道、分辨率R约3800-4900的低分辨率多目标光谱仪（MOS-LR）。该ETC模拟从天体源到探测器的完整光子传播路径，纳入与波长相关的系统吞吐量（望远镜透射率、仪器光学元件、探测器量子效率），通过ESO SkyCalc集成实现精确的天空背景，并采用综合噪声处理（光子噪声、天空背景、读出噪声、暗电流）。计算核心为基于MPDAF框架构建的“pyetc_wst”Python库，支持多种目标光谱能量分布（恒星模板、黑体、幂律、发射线及用户上传的任意红移光谱）与空间形态（点源和Sersic延展轮廓）。四种操作模式支持灵活的曝光时间优化，完整光谱输出包括与波长相关的信噪比（SNR）、源和天空光子计数、按分量分解的噪声以及模拟提取的光谱。交互式网页界面、REST API及命令行工具完善了用户体验，支持批量巡天设计工作流。
英文摘要
We present a comprehensive Exposure Time Calculator (ETC) developed for the Wide-field Spectroscopic Telescope (WST) concept. The WST, currently in its conceptual phase, is designed as a next-generation large spectroscopic survey facility featuring three complementary observing modes: an Integral Field Spectrograph (IFS) covering 370-930 nm at R of about 4800; a high-resolution Multi-Object Spectrograph (MOS-HR) with four bands at R of about 40000; and a low-resolution Multi-Object Spectrograph (MOS-LR) with four channels at R of about 3800-4900. The ETC simulates the complete photon-propagation path from astronomical source to detector, incorporating wavelength-dependent system throughput (telescope transmission, instrumental optics, detector quantum efficiency), accurate sky background via ESO SkyCalc integration, and a comprehensive noise treatment (photon noise, sky background, read-out noise, dark current). The computational core is implemented as the "pyetc_wst" Python library built on the MPDAF framework, supporting multiple target spectral energy distributions (stellar templates, blackbody, power-law, emission lines, and user-uploaded spectra with arbitrary redshift) and spatial morphologies (point sources and Sersic extended profiles). Four operational modes enable flexible exposure-time optimization. Full spectral outputs include wavelength-dependent signal-to-noise ratio (SNR), source and sky photon counts, noise decomposition by component, and simulated extracted spectra. An interactive web interface, together with a REST API and a command-line tool, complete the user experience and enable batch survey-design workflows.
