The PFS/SuMIRe (Prime Focus Spectrograph for the Subaru telescope) is a project involving several Japanese institutions (leaded by IPMU of Univ. of Tokyo), the universities of Caltech, Princeton and Johns Hopkins in the USA, the Laboratory of Astrophysics of Marseille in France, and, in Brazil, USP (Universidade de São Paulo) and LNA ( Laboratório Nacional de Astrofísica) .
This instrument will be capable of capturing 2400 spectra on each pointing of the Subaru telescope, on the optical and near infrared regions. The goals are to map the formation of the first structures in the universe and the formation of the first galaxies at high redshift.
The PFS of the Subaru Measurement of Images and Redshifts (SuMIRe) project has been endorsed by Japanese community as one of the main future instruments of the Subaru 8.2-meter telescope at Mauna Kea, Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology with galaxy surveys, Galactic archaeology, and studies of galaxy/AGN evolution.
Taking advantage of Subaru’s wide field of view, which is further extended with the recently completed Wide Field Corrector, PFS will enable us to carry out multi-fiber spectroscopy of 2400 targets within 1.3 degree diameter. A microlens is attached at each fiber entrance for F-ratio transformation into a larger one so that difficulties of spectrograph design are eased. Fibers are accurately placed onto target positions by positioners, each of which consists of two stages of piezo-electric rotary motors, through iterations by using back-illuminated fiber position measurements with a wide-field metrology camera.
Fibers then carry light to a set of four identical fast-Schmidt spectrographs with three color arms each: the wavelength ranges from 0.38 um to 1.3 um will be simultaneously observed with an average resolving power of 3000.
Before and during the era of extremely large telescopes, PFS will provide the unique capability of obtaining spectra of 2400 cosmological/astrophysical targets simultaneously with an 8-10 meter class telescope.