WFOS: A Wide Field Optical Spectrograph for the Thirty Meter Telescope

摘要

WFOS (Wide Field Optical Spectrograph) will provide near-UV, visible and near-IR multi-object spectroscopy and imaging capabilities for the TMT (Thirty Meter Telescope). The instrument concept is a multi-barrel approach, with four separate fields on the telescope focal plane providing a total of 92.4 square arcminutes of coverage. The core wavelength coverage is 340nm to 1000nm with an optional near-IR extension to 1.6 microns. Each barrel feeds two cameras allowing simultaneous spectral coverage in the blue and red. Spectral resolutions range from R150 to R7500 for a 0.75" slit using standard ruled transmission gratings and VPH technology. A GLAO (Ground Layer Adaptive Optics) system utilizing the TMT adaptive secondary mirror is included hi the instrument concept. This paper describes the scientific goals for WFOS and the overall instrument mechanical, optical and system design.