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 scientific observation in 2025, while continuing to undergo initial adjustment.

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.