Author Submission Conference: Instrument Design and Performance for Optical/Infrared Ground-Based Telescopes (AS08) Chairs: Masanori Iye Alan Moorwood Submitted: 28 January Title: MOIRCS : Multi-Object Infrared Camera and Spectrograph for the Subaru Telescope Principal Author: Chihiro Tokoku Secondary Authors: Takashi Ichikawa, Ryuji Suzuki, Ken'ichiro Asai, Yuka Katsuno (Astronomical Institute, Tohoku University) Koji Omata (Subaru Telescope, National Astronomical Observatory of Japan) Toru Yamada (Optical and IR Astronomy Division, National Astronomical Observatory of Japan) Takashi Tsuda, Toshio Chiba, Atsuo Sasaki (Technical Division, Faculty of Science, Tohoku University) Tetsuo Nishimura (Subaru Telescope, National Astronomical Observatory of Japan) Abstract: MOIRCS (Multi-Object InfraRed Camera and Spectrograph) is one of the second generation instruments for the Subaru Telescope under construction by the National Astronomical Observatory of Japan and Tohoku University. MOIRCS will provide imaging capability from 0.8 um to 2.5 um as well as multi-object spectroscopy across the 4' x 7' field of view at the Cassegrain focus of the Subaru Telescope. The focal plane is imaged onto two 2048x2048 HAWAII 2 HgCdTe arrays at the spatial sampling rate of 0.12"/pixel with slight overlap of the two square fields. All-lens optical design is optimized for z, J, H, and K-bands with emphasis on K-band performance and high throughput. Unique design of MOIRCS allows multi-object spectroscopy at K-band with cooled multi-slit masks. Twenty-four masks are stored in a carrousel dewar and exchangeable in the cryogenic environment. The carrousel has its own vacuum pump and cryogenic refrigerator independently from the MOIRCS main dewar, which is connected with a gate valve. The mask turret inside the carrousel can be accessed for the installation of a new set of masks without breaking the vacuum of the main dewar. The two-channel optics and arrays are mounted back-to-back on a single optical bench in the main dewar together with three turrets each for filters and grisms. A PC-Linux based infrared array control system was designed and optimized for the HAWAII 2 array operation. For other housekeeping tasks we use a commercial instrument control program package. We are targeting first light of MOIRCS in the spring of 2003. Principal Author Affiliation: Astronomical Institute, Tohoku University 650 North A'ohoku Place Hilo , HI 96720 U.S.A. Phone: +1-808-934-5080 Fax: +1-808-934-5984 Principal Author Biography: Chihiro Tokoku is a graduate student of Astronomical Institute, Tohoku University. She received the B.S. in Physics from Tokyo Metropolitan University in 1998, and the M.S. in Astronomy from Tohoku University in 2001. Her research interests are observational study of large scale structure and galaxy evolution in the early universe. She is currently working on the development of MOIRCS for the Subaru Telescope and hopes to utilize the instrument for her research goals. Correspondence for Secondary Authors: Takashi Ichikawa, Ryuji Suzuki, Ken'ichiro Asai, Yuka Katsuno Aoba, Sendai 980-8578, Japan +81-22-217-6500(tel) / +81-22-217-6513(fax) Koji Omata 650 North A'ohoku Place, Hilo, HI 96720, U.S.A +1-808-934-5093(tel) / +1-808-934-5984(fax) Toru Yamada 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan +81-422-34-3587(tel) / +81-422-34-3516(fax) Takashi Tsuda, Toshio Chiba, Atsuo Sasaki Aoba, Sendai 980-8578, Japan +81-22-217-6538(tel) / +81-22-217-6538(fax) Tetsuo Nishimura 650 North A'ohoku Place, Hilo, HI 96720, U.S.A. +1-808-934-5085(tel) / +1-808-934-5984(fax) Presentation Type: Oral Presentation Keywords: Infrared astronomical instrument, near-infrared, infrared camera, multi-object spectroscopy, multi-slit mask, cooled optics, infrared detector array