Development of iodine cells for the Subaru HDS and the Okayama HIDES: I. Instrumentation and performance of the spectrographs

We have developed iodine (I-2) cells for the High Dispersion Spectrograph (HDS) on the Subaru telescope and for the HIgh Dispersion Echelle Spectrograph (HIDES) on the Okayama 1.88 m reflector. The cell is put into a compact vacuum vessel, which fits into a small space behind the entrance slit of the HDS. The cell assembly is designed to minimize heat losses from the cell, which is heated during observations, to keep I-2 vapor from condensation. The amount Of I-2 in the cell is determined to be best suited for radial-velocity measurements of solar-type stars. We also report on some performances of the HDS and HIDES as well as their instrumental profiles based on tests of our I-2 cells. Lastly, we discuss future improvements of our instruments and data-analysis softwares for \I-2 observations, and also describe the scientific goals of our project.