Subaru PFS

The Subaru PFS (Subaru Prime Focus Spectrograph, Prime Focus Spectrograph or PFS) is a multi-object spectrograph on the Subaru Telescope, designed for galaxy surveys for cosmology research. It collects visible light and near infrared, using 2400 optical fibers to simultaneously observe multiple targets over a 1.3 square-degree field. It has three arms, each covering a different band, which image the same slit plane simultaneously. It began operation in early 2025.

The SSP Survey (SSP, Subaru Strategic Program or PFS Subaru Strategic Program) is a planned survey to make use of the PFS, using 300+ nights of observation of target galaxies over a 1400 square-degree survey field that is also covered by HST observation.