Prime Focus Spectrograph (PFS) for the Subaru Telescope: A very wide-field, massively multiplexed, optical and near-infrared spectrograph

Naoyuki Tamura

PFS (Prime Focus Spectrograph), a next generation facility instrument on the 8.2-meter Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394 reconfigurable fibers will be distributed over the 1.3 deg field of view. The spectrograph has been designed with 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm in one exposure at a resolution of ∼1.6−2.7 angstrom. On the Subaru Telescope, Hyper Suprime-Cam (HSC), a very wide-field imager on the prime focus, has already been in science operation and a 5-years survey program in the framework of Subaru Strategic Program (SSP) is ongoing. PFS and HSC are in fact the instrumentation projects under the Subaru Measurement of Images and Redshifts (SuMIRe) project to conduct deep and wide sky surveys exploiting the unique capability of the Subaru Telescope. PFS is therefore expected to start in a timely manner subsequently after the HSC SSP survey. An international collaboration is developing this instrument under the initiative of Kavli IPMU. The instrument development is now going into the construction phase aiming at undertaking system integration in 2017-2018 and subsequently carrying out engineering operations in 2018-2019. In parallel, the PFS science team has been actively developing the survey plan aiming to address key questions in three main fields: cosmology, galaxy & AGN evolution, and Galactic archaeology, and from the joint implications, to understand the dark sector of the universe. The combination of the wide field, high multiplicity, and high number density of the fibers on the focal plane offers a unique opportunity of designing a unique survey on these three core science cases envisioned in the PFS SSP survey. This presentation gives an overview of the instrument, current project status and future paths forward.