National Astronomical Observatory of Japan

Scientific Goals and Missions - Subaru Prime Focus Spectrograph (PFS) Project


The Subaru Prime Focus Spectrograph (PFS) project is to provide a unique capability for Subaru Telescope to realize multi-object spectroscopy over wide-filed and wide-wavelength coverage, aiming to study the origin of the large-scale structure of the universe by conducting very wide field deep survey of the distant universe.


The missions of this project are to develop and implement Prime Focus Spectrograph (PFS) into Subaru Telescope in order to sustain a state-of-the-art observatory and facilitate science for broader communities, leading the design of new scientific requirements for the coming decade and more in astronomical observations at multi-object spectroscopy over wide-filed and wide-wavelength coverage.

Primary Scientific Goals

The primary scientific goal of this project is to realize comprehensive test of Lambda CDM paradigm and go beyond; testing “Lambda” and neutrino mass from cosmology viewpoint, testing nature of dark matter and the assembly history of Milky Way and M31 from Galactic Archaeology viewpoint, and quantifying how galaxies have formed and been shaped under the hierarchical structure formation scenario over cosmic time in view of Galaxy Evolution.

Target Date

End of March 2025