Prime Focus Spectrograph (PFS) for Subaru Telescope: Spectrograph System final integration and performance at LAM and Subaru

The Spectrograph System of Subaru Prime Focus Spectrograph (PFS) is fed by 2400 fibers and consists of four identical spectrograph modules with 4 arms and 600 fibers each. This paper recalls the overall integration process for the spectrograph module series, presents the test procedures and results for the Spectrograph System, the anomalies and issues we overcame in the series, and finally the delivery and installation of four modules at the Subaru Telescope in Hawai`I in 2019, 2022 and 2023. We detail the strategies developed to resolve technical issue such as defocus and tilt encountered after the delivery of the first module for the visible focal planes. We extensively present the optical and thermal performance of the spectrograph system. Finally, we present and discuss lessons learned for the largest 8m-class multi-object spectrograph system.