Oral Presentation

Subaru Prime Focus Spectrograph (PFS) Cosmology Program

Author(s): Tomomi Sunayama (ASIAA)

Presenter: Tomomi Sunayama (ASIAA)

The Prime Focus Spectrograph (PFS) survey is a spectroscopic survey operating on the 8-meter Subaru Telescope. It is designed to observe 2,400 objects simultaneously within a 1.2 deg^2 field of view, covering wavelengths from the near-ultraviolet to the near-infrared. With its wide field and spectral coverage, PFS focuses on three primary science programs: cosmology, galaxy evolution, and galactic archaeology.

For cosmology, PFS will observe ~4 million emission-line galaxies (ELGs) over 1,200 deg², covering redshifts from 0.8 to 2.4. Unlike other surveys, it will uniquely map ELGs at 2.0 < z < 2.4, complementing DESI and Euclid. PFS will provide high-precision measurements of baryon acoustic oscillations (BAO) and the Alcock-Paczyński (AP) effect, enabling constraints on the Hubble expansion history and testing potential evolution in dark energy out to z = 2.4. By combining these results with lower-redshift BAO constraints, PFS will determine the dark energy density to ~7% accuracy per redshift bin. Additionally, redshift-space distortion (RSD) measurements will reconstruct the growth rate of cosmic structure $f\sigma_8(z)$ with 6% accuracy up to z = 2.4, allowing for a precise determination of the sum of neutrino masses, with an uncertainty of $\sigma(\sum m_\nu) = 0.02$. In this talk, I will discuss potential use of these data in the context of cluster science.